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Glenn Randers-Pehrson 1998-01-16 22:06:18 -06:00
parent 2687fcc7b5
commit c4a2ae6cac
26 changed files with 687 additions and 240 deletions
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33
CHANGES
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@ -170,20 +170,33 @@ version 0.96 [May, 1997]
version 0.97 [January, 1998] version 0.97 [January, 1998]
removed PNG_USE_OWN_CRC capability removed PNG_USE_OWN_CRC capability
relocated png_set_crc_action from pngrutil.c to pngrtran.c relocated png_set_crc_action from pngrutil.c to pngrtran.c
fixed typecasts of "new_key", etc. fixed typecasts of "new_key", etc. (Andreas Dilger)
added RFC 1152 date support added RFC 1152 [sic] date support
fixed bug in gamma handling of 4-bit grayscale fixed bug in gamma handling of 4-bit grayscale
added more typecasts. 65536L becomes (png_uint_32)65536L, etc. added 2-bit grayscale gamma handling (Glenn R-P)
added more typecasts. 65536L becomes (png_uint_32)65536L, etc. (Glenn R-P)
minor corrections in libpng.txt minor corrections in libpng.txt
added simple sRGB support added simple sRGB support (Glenn R-P)
make it simpler to do conditional compiling: PNG_READ_NOT_FULLY_SUPPORTED easier conditional compiling, e.g. define PNG_READ/WRITE_NOT_FULLY_SUPPORTED;
fixed memory leak in pngwrite.c (free info_ptr->text) all configurable options can be selected from command-line instead
of having to edit pngconf.h (Glenn R-P)
fixed memory leak in pngwrite.c (free info_ptr->text) (Glenn R-P)
added more conditions for png_do_background, to avoid changing added more conditions for png_do_background, to avoid changing
black pixels to background when a background is supplied and black pixels to background when a background is supplied and
no pixels are transparent no pixels are transparent
repaired PNG_NO_STDIO behaviour repaired PNG_NO_STDIO behaviour
tested NODIV support and made it default behaviour tested NODIV support and made it default behaviour (Greg Roelofs)
added "-m" option to pngtest added "-m" option and PNGTEST_DEBUG_MEMORY to pngtest (John Bowler)
[anything else? 2-bit grayscale gamma bug?]
regularized version numbering scheme and bumped shared-library major regularized version numbering scheme and bumped shared-library major
version number to 2 to avoid potential problems with libpng 0.89 apps version number to 2 to avoid problems with libpng 0.89 apps (Greg Roelofs)
version 0.98 [January, 1998]
cleaned up some typos in libpng.txt and in code documentation
fixed memory leaks in pCAL chunk processing (Glenn R-P and John Bowler)
cosmetic change "display_gamma" to "screen_gamma" in pngrtran.c
changed recommendation about file_gamma for PC images to .51 from .45,
in example.c and libpng.txt, added comments to distinguish between
screen_gamma, viewing_gamma, and display_gamma.
changed all references to RFC1152 to read RFC1123 and changed the
PNG_TIME_RFC1152_SUPPORTED macro to PNG_TIME_RFC1123_SUPPORTED
added png_invert_alpha capability (Glenn R-P -- suggestion by Jon Vincent)
changed srgb_intent from png_byte to int to avoid compiler bugs

34
README
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@ -1,4 +1,4 @@
[NOTE: this is still beta version 0.97c; the text below has already [NOTE: this is still beta version 0.97d; the text below has already
been updated in anticipation of the imminent 1.0 release.] been updated in anticipation of the imminent 1.0 release.]
@ -6,7 +6,7 @@ README for libpng 1.0
This is the first official release of libpng. Don't let the fact that This is the first official release of libpng. Don't let the fact that
it's the first release fool you. The libpng library has been in it's the first release fool you. The libpng library has been in
extensive use and testing for about two years. However, it's extensive use and testing for about two and a half years. However, it's
finally gotten to the stage where there haven't been significant finally gotten to the stage where there haven't been significant
changes to the API in some time, and people have a bad feeling about changes to the API in some time, and people have a bad feeling about
libraries with versions < 1.0. libraries with versions < 1.0.
@ -77,7 +77,7 @@ If not, it should be at ftp.uu.net in /graphics/png
Eventually, it will be at ftp.uu.net in /pub/archiving/zip/zlib Eventually, it will be at ftp.uu.net in /pub/archiving/zip/zlib
You may also want a copy of the PNG specification. It is available You may also want a copy of the PNG specification. It is available
as an Internet Draft, and RFC, and a W3C Recommendation. Failing as an RFC and a W3C Recommendation. Failing
these resources you can try ftp.uu.net in the /graphics/png directory. these resources you can try ftp.uu.net in the /graphics/png directory.
This code is currently being archived at ftp.uu.net in the This code is currently being archived at ftp.uu.net in the
@ -97,19 +97,19 @@ Finally, if you get any warning messages when compiling libpng
fix. Please mention "libpng" somewhere in the subject line. Thanks. fix. Please mention "libpng" somewhere in the subject line. Thanks.
This release was created and will be supported by myself (of course This release was created and will be supported by myself (of course
based in a large way on Guy's earlier work), and the PNG group. based in a large way on Guy's and Andreas' earlier work), and the PNG group.
adilger@enel.ucalgary.ca adilger@enel.ucalgary.ca
png-implement@dworkin.wustl.edu png-implement@dworkin.wustl.edu
You can reach Guy, the original libpng author, at (internet preferred): You can't reach Guy, the original libpng author, at the addresses
given in previous versions of this document. He will read mail
internet: schalnat@group42.com addressed to the png-implement list, however.
CompuServe: 75501,1625
Please do not send general questions about PNG. Send them to Please do not send general questions about PNG. Send them to
the address in the specification. At the same time, please do the address in the specification (png-group@w3.org). At the same
not send libpng questions to that address, send them to me. I'll time, please do not send libpng questions to that address, send them to me
or to png-implement@dworkin.wustl.edu. I'll
get them in the end anyway. If you have a question about something get them in the end anyway. If you have a question about something
in the PNG specification that is related to using libpng, send it in the PNG specification that is related to using libpng, send it
to me. Send me any questions that start with "I was using libpng, to me. Send me any questions that start with "I was using libpng,
@ -132,18 +132,20 @@ Files in this distribution:
descrip.mms => VMS project file descrip.mms => VMS project file
example.c => Example code for using libpng functions example.c => Example code for using libpng functions
libpng.txt => Description of libpng and its functions libpng.txt => Description of libpng and its functions
makefile => Default Unixish makefile
makefile.aco => ACORN makefile makefile.aco => ACORN makefile
makefile.ama => Amiga makefile makefile.ama => Amiga makefile
makefile.atr => Atari makefile makefile.atr => Atari makefile
makefile.bor => Borland makefile makefile.bor => Borland makefile
makefile.dec => DEC makefile
makefile.dj2 => DJGPP 2 makefile makefile.dj2 => DJGPP 2 makefile
makefile.elf => Unix ELF makefile makefile.elf => Unix ELF makefile
makefile.knr => Makefile which calls ansi2knr to convert files makefile.knr => Makefile which calls ansi2knr to convert files
makefile.mip => MIPS makefile makefile.mip => MIPS makefile
makefile.msc => Microsoft C makefile makefile.msc => Microsoft C makefile
makefile.sgi => Silicon Graphics Irix makefile
makefile.std => Standard Unix makefile makefile.std => Standard Unix makefile
makefile.tc => Turbo C makefile makefile.sun => SUN makefile
makefile.tc3 => Turbo C 3.0 makefile
makevms.com => VMS make program makevms.com => VMS make program
png.c => Basic interface functions common to library png.c => Basic interface functions common to library
png.h => Library function and interface declarations png.h => Library function and interface declarations
@ -166,13 +168,15 @@ Files in this distribution:
Good luck, and happy coding. Good luck, and happy coding.
-Glenn Randers-Pehrson
Internet: randeg@alumni.rpi.edu
Web: http://www.rpi.edu/~randeg/index.html
-Andreas Eric Dilger -Andreas Eric Dilger
Internet: adilger@enel.ucalgary.ca Internet: adilger@enel.ucalgary.ca
Web: http://www-mddsp.enel.ucalgary.ca/People/adilger/ Web: http://www-mddsp.enel.ucalgary.ca/People/adilger/
-Guy Eric Schalnat -Guy Eric Schalnat
Group 42, Inc. (formerly of Group 42, Inc)
Internet: schalnat@group42.com
CompuServe: 75501,1625
Web: http://www.group42.com/ Web: http://www.group42.com/

2
TODO
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@ -5,7 +5,7 @@ improved dithering
multi-lingual error and warning message support multi-lingual error and warning message support
sPLT chunk handling sPLT chunk handling
cHRM transformation cHRM transformation
complete sRGB transformation (presently it simply uses gamma=0.5) complete sRGB transformation (presently it simply uses gamma=0.51)
man pages for function calls man pages for function calls
high-level API for reading images high-level API for reading images
final bug fixes final bug fixes

16
example.c
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@ -190,19 +190,22 @@ void read_png(FILE *fp, unsigned int sig_read) /* file is already open */
PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0); PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0);
/* Some suggestions as to how to get a screen gamma value */ /* Some suggestions as to how to get a screen gamma value */
/* Note that screen gamma is (display_gamma/viewing_gamma)
if (/* We have a user-defined screen gamma value */) if (/* We have a user-defined screen gamma value */)
{ {
screen_gamma = user-defined screen_gamma; screen_gamma = user-defined screen_gamma;
} }
/* This is one way that applications share the same screen gamma value */ /* This is one way that applications share the same screen gamma value */
else if ((gamma_str = getenv("DISPLAY_GAMMA")) != NULL) else if ((gamma_str = getenv("SCREEN_GAMMA")) != NULL)
{ {
screen_gamma = atof(gamma_str); screen_gamma = atof(gamma_str);
} }
/* If we don't have another value */ /* If we don't have another value */
else else
{ {
screen_gamma = 2.2; /* A good guess for PC monitors */ screen_gamma = 2.2; /* A good guess for a PC monitors in a brightly
lit room */
screen_gamma = 1.7 or 1.0; /* A good guess for Mac systems */ screen_gamma = 1.7 or 1.0; /* A good guess for Mac systems */
} }
@ -211,13 +214,16 @@ void read_png(FILE *fp, unsigned int sig_read) /* file is already open */
* by the user at run time by the user. It is strongly suggested that * by the user at run time by the user. It is strongly suggested that
* your application support gamma correction. * your application support gamma correction.
*/ */
if (png_get_sRGB(png_ptr, info_ptr, &srgb_intent)
png_set_sRGB(png_ptr, srgb_intent, 0); int intent;
if (png_get_sRGB(png_ptr, info_ptr, &intent)
png_set_sRGB(png_ptr, intent, 0);
else else
if (png_get_gAMA(png_ptr, info_ptr, &image_gamma) if (png_get_gAMA(png_ptr, info_ptr, &image_gamma)
png_set_gamma(png_ptr, screen_gamma, image_gamma); png_set_gamma(png_ptr, screen_gamma, image_gamma);
else else
png_set_gamma(png_ptr, screen_gamma, 0.45); png_set_gamma(png_ptr, screen_gamma, 0.51);
/* Dither RGB files down to 8 bit palette or reduce palettes /* Dither RGB files down to 8 bit palette or reduce palettes
* to the number of colors available on your screen. * to the number of colors available on your screen.

161
libpng.txt
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@ -1,10 +1,13 @@
libpng.txt - a description on how to use and modify libpng libpng.txt - a description on how to use and modify libpng
libpng version 1.00 version 0.97 libpng version 0.98
Updated and distributed by Glenn Randers-Pehrson <randeg@alumni.rpi.edu>
Copyright (c) 1998, Glenn Randers-Pehrson
January 16, 1998
based on: based on:
libpng version 1.00 version 0.96 libpng 1.0 beta 6 version 0.96
Updated and distributed by Andreas Dilger <adilger@enel.ucalgary.ca>, Updated and distributed by Andreas Dilger <adilger@enel.ucalgary.ca>,
Copyright (c) 1996, 1997 Andreas Dilger Copyright (c) 1996, 1997 Andreas Dilger
May 28, 1997 May 28, 1997
@ -29,7 +32,7 @@ it is heavily commented and should include everything most people
will need. will need.
Libpng was written as a companion to the PNG specification, as a way Libpng was written as a companion to the PNG specification, as a way
to reduce the amount of time and effort it takes to support the PNG of reducing the amount of time and effort it takes to support the PNG
file format in application programs. The PNG specification is available file format in application programs. The PNG specification is available
as RFC 2083 <ftp://ftp.uu.net/graphics/png/documents/> and as a as RFC 2083 <ftp://ftp.uu.net/graphics/png/documents/> and as a
W3C Recommendation <http://www.w3.org/pub/WWW/TR/REC.png.html>. Some W3C Recommendation <http://www.w3.org/pub/WWW/TR/REC.png.html>. Some
@ -49,12 +52,14 @@ machines (ANSI, K&R, 16-, 32-, and 64-bit) available, and to be easy
to use. The ultimate goal of libpng is to promote the acceptance of to use. The ultimate goal of libpng is to promote the acceptance of
the PNG file format in whatever way possible. While there is still the PNG file format in whatever way possible. While there is still
work to be done (see the TODO file), libpng should cover the work to be done (see the TODO file), libpng should cover the
majority of the needs of it's users. majority of the needs of its users.
Libpng uses zlib for its compression and decompression of PNG files. Libpng uses zlib for its compression and decompression of PNG files.
The zlib compression utility is a general purpose utility that is The zlib compression utility is a general purpose utility that is
useful for more than PNG files, and can be used without libpng. useful for more than PNG files, and can be used without libpng.
See the documentation delivered with zlib for more details. See the documentation delivered with zlib for more details.
You can usually find the source files for the zlib utility wherever you
find the libpng source files.
Libpng is thread safe, provided the threads are using different Libpng is thread safe, provided the threads are using different
instances of the structures. Each thread should have its own instances of the structures. Each thread should have its own
@ -69,13 +74,15 @@ II. Structures
There are two main structures that are important to libpng, png_struct There are two main structures that are important to libpng, png_struct
and png_info. The first, png_struct, is an internal structure that and png_info. The first, png_struct, is an internal structure that
will not, for the most part, be used by a user except as the first will not, for the most part, be used by a user except as the first
variable passed to every libpng function call. variable passed to every libpng function call. It is not actually
used in many of the functions; do not be alarmed about compiler
warnings that say something to the effect that "png_ptr is not used."
The png_info structure is designed to provide information about the The png_info structure is designed to provide information about the
PNG file. At one time, the fields of png_info were intended to be PNG file. At one time, the fields of png_info were intended to be
directly accessible to the user. However, this tended to cause problems directly accessible to the user. However, this tended to cause problems
with applications using dynamically loaded libraries, and as a result with applications using dynamically loaded libraries, and as a result
a set of interface functions for png_info were delevoped. The fields a set of interface functions for png_info was developed. The fields
of png_info are still available for older applications, but it is of png_info are still available for older applications, but it is
suggested that applications use the new interfaces if at all possible. suggested that applications use the new interfaces if at all possible.
@ -193,6 +200,19 @@ libpng know that there are some bytes missing from the start of the file.
png_set_sig_bytes(png_ptr, number); png_set_sig_bytes(png_ptr, number);
In PNG files, the alpha channel in an image is the level of opacity.
If you need the alpha channel in an image to be the level of transparency
instead of opacity, you can invert the alpha channel (or the tRNS chunk
data) after it's read, so that 0 is fully opaque and 255 (in 8-bit or
paletted images) or 65535 (in 16-bit images) is fully transparent, with
png_set_invert_alpha(png_ptr);
This has to appear here rather than later with the other transformations
because the tRNS chunk data must be modified in the case of paletted images.
If your image is not a paletted image, the tRNS data (which in such cases
represents a single color to be rendered as transparent) won't be changed.
You are now ready to read all the file information up to the actual You are now ready to read all the file information up to the actual
image data. You do this with a call to png_read_info(). image data. You do this with a call to png_read_info().
@ -252,6 +272,12 @@ into the info_ptr is returned for any complex types.
png_get_gAMA(png_ptr, info_ptr, &gamma); png_get_gAMA(png_ptr, info_ptr, &gamma);
gamma - the gamma the file is written at (PNG_INFO_gAMA) gamma - the gamma the file is written at (PNG_INFO_gAMA)
png_get_sRGB(png_ptr, info_ptr, &srgb_intent);
srgb_intent - the rendering intent (PNG_INFO_sRGB)
The presence of the sRGB chunk means that the pixel
data is in the sRGB color space. This chunk also
implies specific values of gAMA and cHRM.
png_get_sBIT(png_ptr, info_ptr, &sig_bit); png_get_sBIT(png_ptr, info_ptr, &sig_bit);
sig_bit - the number of significant bits for (PNG_INFO_sBIT) sig_bit - the number of significant bits for (PNG_INFO_sBIT)
the gray, red, green, and blue channels, whichever the gray, red, green, and blue channels, whichever
@ -301,9 +327,9 @@ keyword/text pairs, one pair per chunk, with no limit on the number
of text chunks, and a 2^31 byte limit on their size. While there are of text chunks, and a 2^31 byte limit on their size. While there are
suggested keywords, there is no requirement to restrict the use to these suggested keywords, there is no requirement to restrict the use to these
strings. It is strongly suggested that keywords and text be sensible strings. It is strongly suggested that keywords and text be sensible
to humans (that's the point), so don't use abbreviations or non-printing to humans (that's the point), so don't use abbreviations. Non-printing
symbols. See the PNG specification for more details. There is also symbols are not allowed. See the PNG specification for more details.
no requirement to have text after the keyword. There is also no requirement to have text after the keyword.
Keywords should be limited to 79 Latin-1 characters without leading or Keywords should be limited to 79 Latin-1 characters without leading or
trailing spaces, but non-consecutive spaces are allowed within the trailing spaces, but non-consecutive spaces are allowed within the
@ -381,7 +407,7 @@ values of the pixels:
png_set_packing(png_ptr); png_set_packing(png_ptr);
PNG files have possible bit depths of 1, 2, 4, 8, and 16. All pixels PNG files have possible bit depths of 1, 2, 4, 8, and 16. All pixels
stored in a PNG image whave been "scaled" or "shifted" up to the next stored in a PNG image have been "scaled" or "shifted" up to the next
higher possible bit depth (eg from 5 bits/sample in the range [0,31] to higher possible bit depth (eg from 5 bits/sample in the range [0,31] to
8 bits/sample in the range [0, 255]). However, it is also possible to 8 bits/sample in the range [0, 255]). However, it is also possible to
convert the PNG pixel data back to the original bit depth of the image. convert the PNG pixel data back to the original bit depth of the image.
@ -429,7 +455,7 @@ color. If the PNG file contains a bKGD chunk (PNG_INFO_bKGD valid),
you may use this color, or supply another color more suitable for you may use this color, or supply another color more suitable for
the current display (e.g., the background color from a web page). You the current display (e.g., the background color from a web page). You
need to tell libpng whether the color is in the gamma space of the need to tell libpng whether the color is in the gamma space of the
dispay (PNG_BACKGROUND_GAMMA_SCREEN for colors you supply), the file display (PNG_BACKGROUND_GAMMA_SCREEN for colors you supply), the file
(PNG_BACKGROUND_GAMMA_FILE for colors from the bKGD chunk), or one (PNG_BACKGROUND_GAMMA_FILE for colors from the bKGD chunk), or one
that is neither of these gammas (PNG_BACKGROUND_GAMMA_UNIQUE - I don't that is neither of these gammas (PNG_BACKGROUND_GAMMA_UNIQUE - I don't
know why anyone would use this, but it's here). know why anyone would use this, but it's here).
@ -457,28 +483,39 @@ To properly display PNG images on any kind of system, the application needs
to know what the display gamma is. Ideally, the user will know this, and to know what the display gamma is. Ideally, the user will know this, and
the application will allow them to set it. One method of allowing the user the application will allow them to set it. One method of allowing the user
to set the display gamma separately for each system is to check for the to set the display gamma separately for each system is to check for the
DISPLAY_GAMMA environment variable, which will hopefully be correctly set. DISPLAY_GAMMA and VIEWING_GAMMA environment variables or for a SCREEN_GAMMA
environment variable, which will hopefully be correctly set.
Note that display_gamma is the gamma of your display, while screen_gamma is
the overall gamma correction required to produce pleasing results,
which depends on the lighting conditions in the surrounding environment.
Screen_gamma is display_gamma/viewing_gamma, where viewing_gamma is
the amount of additional gamma correction needed to compensate for
a dim (viewing_gamma=1.125) or dark (viewing_gamma=1.25) environment.
In a brightly lit room, no compensation other than the display_gamma
is needed (viewing_gamma=1.0).
if (/* We have a user-defined screen gamma value */) if (/* We have a user-defined screen gamma value */)
{ {
screen_gamma = user_defined_screen_gamma; screen_gamma = user_defined_screen_gamma;
} }
/* One way that applications can share the same screen gamma value */ /* One way that applications can share the same screen gamma value */
else if ((gamma_str = getenv("DISPLAY_GAMMA")) != NULL) else if ((gamma_str = getenv("SCREEN_GAMMA")) != NULL)
{ {
screen_gamma = atof(gamma_str); screen_gamma = atof(gamma_str);
} }
/* If we don't have another value */ /* If we don't have another value */
else else
{ {
screen_gamma = 2.2; /* A good guess for PC monitors */ screen_gamma = 2.2; /* A good guess for a PC monitor in a bright office */
screen_gamma = 1.956; /* A good guess for a PC monitor in a dim room */
screen_gamma = 1.7 or 1.0; /* A good guess for Mac systems */ screen_gamma = 1.7 or 1.0; /* A good guess for Mac systems */
} }
The png_set_gamma() function handles gamma transformations of the data. The png_set_gamma() function handles gamma transformations of the data.
Pass both the file gamma and the current screen_gamma. If the file does Pass both the file gamma and the current screen_gamma. If the file does
not have a gamma value, you can pass one anyway if you have an idea what not have a gamma value, you can pass one anyway if you have an idea what
it is (usually 0.45 is a good guess for GIF images on PCs). Note it is (usually 0.51 is a good guess for GIF images on PCs). Note
that file gammas are inverted from screen gammas. See the discussions that file gammas are inverted from screen gammas. See the discussions
on gamma in the PNG specification for an excellent description of what on gamma in the PNG specification for an excellent description of what
gamma is, and why all applications should support it. It is strongly gamma is, and why all applications should support it. It is strongly
@ -487,7 +524,7 @@ recommended that PNG viewers support gamma correction.
if (png_get_gAMA(png_ptr, info_ptr, &gamma)) if (png_get_gAMA(png_ptr, info_ptr, &gamma))
png_set_gamma(png_ptr, screen_gamma, gamma); png_set_gamma(png_ptr, screen_gamma, gamma);
else else
png_set_gamma(png_ptr, screen_gamma, 0.45); png_set_gamma(png_ptr, screen_gamma, 0.51);
If you need to reduce an RGB file to a paletted file, or if a paletted If you need to reduce an RGB file to a paletted file, or if a paletted
file has more entries then will fit on your screen, png_set_dither() file has more entries then will fit on your screen, png_set_dither()
@ -544,7 +581,7 @@ need to change the order the pixels are packed into bytes, you can use:
The last thing to handle is interlacing; this is covered in detail below, The last thing to handle is interlacing; this is covered in detail below,
but you must call the function here. but you must call the function here.
number_passes = png_set_interlace_handling(png_ptr); number_of_passes = png_set_interlace_handling(png_ptr);
After setting the transformations, libpng can update your png_info After setting the transformations, libpng can update your png_info
structure to reflect any transformations you've requested with this structure to reflect any transformations you've requested with this
@ -582,7 +619,7 @@ where row_pointers is:
You can point to void or char or whatever you use for pixels. You can point to void or char or whatever you use for pixels.
If you don't want to read int the whole image at once, you can If you don't want to read in the whole image at once, you can
use png_read_rows() instead. If there is no interlacing (check use png_read_rows() instead. If there is no interlacing (check
interlace_type == PNG_INTERLACE_TYPE_NONE), this is simple: interlace_type == PNG_INTERLACE_TYPE_NONE), this is simple:
@ -599,24 +636,24 @@ row_pointers:
If the file is interlaced (info_ptr->interlace_type != 0), things get If the file is interlaced (info_ptr->interlace_type != 0), things get
somewhat harder. The only current (PNG Specification version 1.0) somewhat harder. The only current (PNG Specification version 1.0)
interlacing type for PNG is (interlace_type == PNG_INTERLACE_TYPE_ADAM7) interlacing type for PNG is (interlace_type == PNG_INTERLACE_TYPE_ADAM7)
is a someewhat complicated 2D interlace scheme, known as Adam7, that is a somewhat complicated 2D interlace scheme, known as Adam7, that
breaks down an image into seven smaller images of varying size, based breaks down an image into seven smaller images of varying size, based
on an 8x8 grid. on an 8x8 grid.
libpng can fill out those images or it can give them to you "as is". libpng can fill out those images or it can give them to you "as is".
If you want them filled out, there are two ways to do that. The one If you want them filled out, there are two ways to do that. The one
mentioned in the PNG specification is to expand each pixel to cover mentioned in the PNG specification is to expand each pixel to cover
those pixels that have not been read yet. This results in a blocky those pixels that have not been read yet (the "rectangle" method).
image for the first pass, which gradually smoothes out as more pixels This results in a blocky image for the first pass, which gradually
are read. The other method is the "sparkle" method, where pixels are smooths out as more pixels are read. The other method is the "sparkle"
draw only in their final locations, with the rest of the image remaining method, where pixels are drawn only in their final locations, with the
whatever colors they were initialized to before the start of the read. rest of the image remaining whatever colors they were initialized to
The first method usually looks better, but tends to be slower, as there before the start of the read. The first method usually looks better,
are more pixels to put in the rows. but tends to be slower, as there are more pixels to put in the rows.
If you don't want libpng to handle the interlacing details, just call If you don't want libpng to handle the interlacing details, just call
png_read_rows() seven times to read in all seven images. Each of the png_read_rows() seven times to read in all seven images. Each of the
images are valid images by themselves, or they can be combined on an images is a valid image by itself, or they can all be combined on an
8x8 grid to form a single image (although if you intend to combine them 8x8 grid to form a single image (although if you intend to combine them
you would be far better off using the libpng interlace handling). you would be far better off using the libpng interlace handling).
@ -638,7 +675,7 @@ If you want libpng to expand the images, call this before calling
png_start_read_image() or png_read_update_info(): png_start_read_image() or png_read_update_info():
if (interlace_type == PNG_INTERLACE_TYPE_ADAM7) if (interlace_type == PNG_INTERLACE_TYPE_ADAM7)
number_passes = png_set_interlace_handling(png_ptr); number_of_passes = png_set_interlace_handling(png_ptr);
This will return the number of passes needed. Currently, this This will return the number of passes needed. Currently, this
is seven, but may change if another interlace type is added. is seven, but may change if another interlace type is added.
@ -649,12 +686,12 @@ If you are not going to display the image after each pass, but are
going to wait until the entire image is read in, use the sparkle going to wait until the entire image is read in, use the sparkle
effect. This effect is faster and the end result of either method effect. This effect is faster and the end result of either method
is exactly the same. If you are planning on displaying the image is exactly the same. If you are planning on displaying the image
after each pass, the rectangle effect is generally considered the after each pass, the "rectangle" effect is generally considered the
better looking one. better looking one.
If you only want the "sparkle" effect, just call png_read_rows() as If you only want the "sparkle" effect, just call png_read_rows() as
normal, with the third parameter NULL. Make sure you make pass over normal, with the third parameter NULL. Make sure you make pass over
the image number_passes times, and you don't change the data in the the image number_of_passes times, and you don't change the data in the
rows between calls. You can change the locations of the data, just rows between calls. You can change the locations of the data, just
not the data. Each pass only writes the pixels appropriate for that not the data. Each pass only writes the pixels appropriate for that
pass, and assumes the data from previous passes is still valid. pass, and assumes the data from previous passes is still valid.
@ -963,6 +1000,19 @@ Some of the more important parts of the png_info are:
png_set_gAMA(png_ptr, info_ptr, gamma); png_set_gAMA(png_ptr, info_ptr, gamma);
gamma - the gamma the image was created at (PNG_INFO_gAMA) gamma - the gamma the image was created at (PNG_INFO_gAMA)
png_set_sRGB(png_ptr, info_ptr, srgb_intent);
srgb_intent - the rendering intent (PNG_INFO_sRGB)
The presence of the sRGB chunk means that the pixel
data is in the sRGB color space. This chunk also
implies specific values of gAMA and cHRM.
png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, srgb_intent);
srgb_intent - the rendering intent (PNG_INFO_sRGB)
The presence of the sRGB chunk means that the pixel
data is in the sRGB color space. This chunk also
causes gAMA and cHRM chunks with the specific values
that are consistent with sRGB to be written.
png_set_sBIT(png_ptr, info_ptr, sig_bit); png_set_sBIT(png_ptr, info_ptr, sig_bit);
sig_bit - the number of significant bits for (PNG_INFO_sBIT) sig_bit - the number of significant bits for (PNG_INFO_sBIT)
the gray, red, green, and blue channels, whichever the gray, red, green, and blue channels, whichever
@ -996,11 +1046,25 @@ Some of the more important parts of the png_info are:
offset_y - positive offset from the top edge of the screen offset_y - positive offset from the top edge of the screen
unit_type - PNG_OFFSET_PIXEL, PNG_OFFSET_MICROMETER unit_type - PNG_OFFSET_PIXEL, PNG_OFFSET_MICROMETER
png_get_pHYs(png_ptr, info_ptr, res_x, res_y, unit_type); png_set_pHYs(png_ptr, info_ptr, res_x, res_y, unit_type);
res_x - pixels/unit physical resolution in x direction res_x - pixels/unit physical resolution in x direction
res_y - pixels/unit physical resolution in x direction res_y - pixels/unit physical resolution in x direction
unit_type - PNG_RESOLUTION_UNKOWN, PNG_RESOLUTION_METER unit_type - PNG_RESOLUTION_UNKOWN, PNG_RESOLUTION_METER
In PNG files, the alpha channel in an image is the level of opacity.
If your data is supplied as a level of transparency, you can invert the
alpha channel before you write it, so that 0 is fully transparent and 255
(in 8-bit or paletted images) or 65535 (in 16-bit images) is fully opaque,
with
png_set_invert_alpha(png_ptr);
This must appear here instead of later with the other transformations
because in the case of paletted images the tRNS chunk data has to
be inverted before the tRNS chunk is written. If your image is not a
paletted image, the tRNS data (which in such cases represents a single
color to be rendered as transparent) won't be changed.
A quick word about text and num_text. text is an array of png_text A quick word about text and num_text. text is an array of png_text
structures. num_text is the number of valid structures in the array. structures. num_text is the number of valid structures in the array.
If you want, you can use max_text to hold the size of the array, but If you want, you can use max_text to hold the size of the array, but
@ -1072,8 +1136,8 @@ tEXt chunk use RFC 1123 format dates (eg 22 May 1997 18:07:10 GMT"),
although this isn't a requirement. Unlike the tIME chunk, the although this isn't a requirement. Unlike the tIME chunk, the
"Creation Time" tEXt chunk is not expected to be automatically changed "Creation Time" tEXt chunk is not expected to be automatically changed
by the software. To facilitate the use of RFC 1123 dates, a function by the software. To facilitate the use of RFC 1123 dates, a function
png_convert_to_rfc1152(png_timep) is provided to convert from PNG png_convert_to_rfc1123(png_timep) is provided to convert from PNG
time to an RFC 1152 format string. time to an RFC 1123 format string.
You are now ready to write all the file information up to the actual You are now ready to write all the file information up to the actual
image data. You do this with a call to png_write_info(). image data. You do this with a call to png_write_info().
@ -1229,12 +1293,12 @@ correct number of times to write all seven sub-images.
If you want libpng to build the sub-images, call this before you start If you want libpng to build the sub-images, call this before you start
writing any rows: writing any rows:
number_passes = png_set_interlace_handling(png_ptr); number_of_passes = png_set_interlace_handling(png_ptr);
This will return the number of passes needed. Currently, this This will return the number of passes needed. Currently, this
is seven, but may change if another interlace type is added. is seven, but may change if another interlace type is added.
Then write the complete image number_passes times. Then write the complete image number_of_passes times.
png_write_rows(png_ptr, row_pointers, number_of_rows); png_write_rows(png_ptr, row_pointers, number_of_rows);
@ -1280,7 +1344,7 @@ MAXSEG_64K in zlib.h. Since it is unlikely that the method of handling
memory allocation on a platform will change between applications, these memory allocation on a platform will change between applications, these
functions must be modified in the library at compile time. functions must be modified in the library at compile time.
Input/Output in libpng is done throught png_read() and png_write(), Input/Output in libpng is done through png_read() and png_write(),
which currently just call fread() and fwrite(). The FILE * is stored in which currently just call fread() and fwrite(). The FILE * is stored in
png_struct and is initialized via png_init_io(). If you wish to change png_struct and is initialized via png_init_io(). If you wish to change
the method of I/O, the library supplies callbacks that you can set the method of I/O, the library supplies callbacks that you can set
@ -1378,7 +1442,7 @@ call. See zlib.h or zconf.h in the zlib library for more information.
Configuring for Medium Model: Configuring for Medium Model:
Libpng's support for medium model has been tested on most of the popular Libpng's support for medium model has been tested on most of the popular
complers. Make sure MAXSEG_64K gets defined, USE_FAR_KEYWORD gets compilers. Make sure MAXSEG_64K gets defined, USE_FAR_KEYWORD gets
defined, and FAR gets defined to far in pngconf.h, and you should be defined, and FAR gets defined to far in pngconf.h, and you should be
all set. Everything in the library (except for zlib's structure) is all set. Everything in the library (except for zlib's structure) is
expecting far data. You must use the typedefs with the p or pp on expecting far data. You must use the typedefs with the p or pp on
@ -1410,8 +1474,8 @@ most useful one changes the compression level, which currently uses
input compression values in the range 0 - 9. The library normally input compression values in the range 0 - 9. The library normally
uses the default compression level (Z_DEFAULT_COMPRESSION = 6). Tests uses the default compression level (Z_DEFAULT_COMPRESSION = 6). Tests
have shown that for a large majority of images, compression values in have shown that for a large majority of images, compression values in
the range 3-6 compress as well as higher levels, and do so much faster. the range 3-6 compress nearly as well as higher levels, and do so much
For online applications it may be desirable to have maximum speed faster. For online applications it may be desirable to have maximum speed
(Z_BEST_SPEED = 1). With versions of zlib after v0.99, you can also (Z_BEST_SPEED = 1). With versions of zlib after v0.99, you can also
specify no compression (Z_NO_COMPRESSION = 0), but this would create specify no compression (Z_NO_COMPRESSION = 0), but this would create
files larger than just storing the raw bitmap. You can specify the files larger than just storing the raw bitmap. You can specify the
@ -1495,8 +1559,13 @@ Removing unwanted object code:
There are a bunch of #define's in pngconf.h that control what parts of There are a bunch of #define's in pngconf.h that control what parts of
libpng are compiled. All the defines end in _SUPPORTED. If you are libpng are compiled. All the defines end in _SUPPORTED. If you are
never going to use an ability, you can change the #define to #undef never going to use an ability, you can change the #define to #undef
before recompiling libpng and save yourself code and data space. All before recompiling libpng and save yourself code and data space.
the reading and writing specific code are in seperate files, so the You can also turn them off en masse with a compiler directive to
define PNG_READ_NOT_FULLY_SUPPORTED or PNG_WRITE_NOT_FULLY_SUPPORTED,
along with directives to turn on any of the capabilities that you do
want.
All the reading and writing specific code are in separate files, so the
linker should only grab the files it needs. However, if you want to linker should only grab the files it needs. However, if you want to
make sure, or if you are building a stand alone library, all the make sure, or if you are building a stand alone library, all the
reading files start with pngr and all the writing files start with reading files start with pngr and all the writing files start with
@ -1514,10 +1583,12 @@ those sections which are actually used will be loaded into memory.
Changes to Libpng from version 0.88 Changes to Libpng from version 0.88
It should be noted that versions of libpng later than 0.88 are not It should be noted that versions of libpng later than 0.96 are not
distributed by the original libpng author, Guy Schalnat, but rather distributed by the original libpng author, Guy Schalnat, nor by
another member of the original PNG Group, Andreas Dilger. Guy is still Andreas Dilger, who had taken over from Guy during 1996 and 1997, and
alive and well, but he has moved on to other things. distributed versions 0.89 through 0.96, but rather by another member
of the original PNG Group, Glenn Randers-Pehrson. Guy and Andreas are
still alive and well, but they have moved on to other things.
The old libpng functions png_read_init(), png_write_init(), The old libpng functions png_read_init(), png_write_init(),
png_info_init(), png_read_destroy(), and png_write_destory() have been png_info_init(), png_read_destroy(), and png_write_destory() have been

4
makefile.elf
View File

@ -1,6 +1,6 @@
# makefile for libpng on Linux ELF with gcc # makefile for libpng on Linux ELF with gcc
# Copyright (C) 1996, 1997 Andreas Dilger # Copyright (C) 1996, 1997 Andreas Dilger
# Copyright (C) 1998 Glenn Randers-Pehrson # Copyright (C) 1998 Greg Roelofs
# For conditions of distribution and use, see copyright notice in png.h # For conditions of distribution and use, see copyright notice in png.h
CC=gcc CC=gcc
@ -22,7 +22,7 @@ RANLIB=ranlib
#RANLIB=echo #RANLIB=echo
PNGMAJ = 2 PNGMAJ = 2
PNGMIN = 0.97 PNGMIN = 0.98
PNGVER = $(PNGMAJ).$(PNGMIN) PNGVER = $(PNGMAJ).$(PNGMIN)
# where make install puts libpng.a, libpng.so*, and png.h # where make install puts libpng.a, libpng.so*, and png.h

69
makefile.sgi Normal file
View File

@ -0,0 +1,69 @@
# makefile for libpng
# Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
# For conditions of distribution and use, see copyright notice in png.h
# Where the zlib library and include files are located
#ZLIBLIB=/usr/local/lib
#ZLIBINC=/usr/local/include
ZLIBLIB=../zlib
ZLIBINC=../zlib
CC=cc
CFLAGS=-I$(ZLIBINC) -O -fullwarn # -g -DPNG_DEBUG=1
LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lz -lm
RANLIB=echo
#RANLIB=ranlib
# where make install puts libpng.a and png.h
prefix=/usr/local
OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
pngwtran.o pngmem.o pngerror.o pngpread.o
all: libpng.a pngtest
libpng.a: $(OBJS)
ar rc $@ $(OBJS)
$(RANLIB) $@
pngtest: pngtest.o libpng.a
$(CC) -o pngtest $(CCFLAGS) pngtest.o $(LDFLAGS)
test: pngtest
./pngtest
install: libpng.a
-@mkdir $(prefix)/include
-@mkdir $(prefix)/lib
cp png.h $(prefix)/include
cp pngconf.h $(prefix)/include
chmod 644 $(prefix)/include/png.h
chmod 644 $(prefix)/include/pngconf.h
cp libpng.a $(prefix)/lib
chmod 644 $(prefix)/lib/libpng.a
clean:
rm -f *.o libpng.a pngtest pngout.png
# DO NOT DELETE THIS LINE -- make depend depends on it.
png.o: png.h pngconf.h
pngerror.o: png.h pngconf.h
pngrio.o: png.h pngconf.h
pngwio.o: png.h pngconf.h
pngmem.o: png.h pngconf.h
pngset.o: png.h pngconf.h
pngget.o: png.h pngconf.h
pngread.o: png.h pngconf.h
pngrtran.o: png.h pngconf.h
pngrutil.o: png.h pngconf.h
pngtest.o: png.h pngconf.h
pngtrans.o: png.h pngconf.h
pngwrite.o: png.h pngconf.h
pngwtran.o: png.h pngconf.h
pngwutil.o: png.h pngconf.h
pngpread.o: png.h pngconf.h

2
makefile.tc → makefile.tc3
View File

@ -1,7 +1,7 @@
# Makefile for libpng # Makefile for libpng
# TurboC++ 3.0 (Note: All modules are compiled in C mode) # TurboC++ 3.0 (Note: All modules are compiled in C mode)
# To use, do "make -fmakefile.tc" # To use, do "make -fmakefile.tc3"
# ------------- Turbo C++ 3.0 ------------- # ------------- Turbo C++ 3.0 -------------
MODEL=-ml MODEL=-ml

6
png.c
View File

@ -1,12 +1,12 @@
/* png.c - location for general purpose libpng functions /* png.c - location for general purpose libpng functions
* *
* libpng 0.97 * libpng 0.98
* For conditions of distribution and use, see copyright notice in png.h * For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
* Copyright (c) 1996, 1997 Andreas Dilger * Copyright (c) 1996, 1997 Andreas Dilger
* Copyright (c) 1998, Glenn Randers-Pehrson * Copyright (c) 1998, Glenn Randers-Pehrson
* January 7, 1998 * January 16, 1998
*/ */
#define PNG_INTERNAL #define PNG_INTERNAL
@ -16,7 +16,7 @@
/* Version information for C files. This had better match the version /* Version information for C files. This had better match the version
* string defined in png.h. * string defined in png.h.
*/ */
char png_libpng_ver[] = "0.97"; char png_libpng_ver[] = "0.98";
/* Place to hold the signiture string for a PNG file. */ /* Place to hold the signiture string for a PNG file. */
png_byte FARDATA png_sig[8] = {137, 80, 78, 71, 13, 10, 26, 10}; png_byte FARDATA png_sig[8] = {137, 80, 78, 71, 13, 10, 26, 10};

104
png.h
View File

@ -1,12 +1,37 @@
/* png.h - header file for PNG reference library /* png.h - header file for PNG reference library
* *
* libpng 0.97 beta * libpng 0.98 beta
* For conditions of distribution and use, see copyright notice in png.h * For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
* Copyright (c) 1996, 1997 Andreas Dilger * Copyright (c) 1996, 1997 Andreas Dilger
* Copyright (c) 1998 Glenn Randers-Pehrson * Copyright (c) 1998 Glenn Randers-Pehrson
* January 7, 1998 * January 16, 1998
*
* Note about libpng version numbers:
*
* Due to various miscommunications, unforeseen code incompatibilities
* and occasional factors outside the authors' control, version numbering
* on the library has not always been consistent and straightforward.
* The following table summarizes matters since version 0.89c, which was
* the first widely used release:
*
* source png.h shared-lib
* version string version
* ------- ------ ----------
* 0.89c ("1.0 beta 3") 0.89 1.0.89
* 0.90 ("1.0 beta 4") 0.90 0.90 [should have been 2.0.90]
* 0.95 ("1.0 beta 5") 0.95 0.95 [should have been 2.0.95]
* 0.96 ("1.0 beta 6") 0.96 0.96 [should have been 2.0.96]
* 0.97b ("1.00.97 beta 7") 1.00.97 1.0.0 [should have been 2.0.97]
* 0.97c 0.97 2.0.97
* 0.98 0.98 2.0.98
* 0.99 0.99 2.0.99
* 1.0 1.00 2.1.0
*
* Henceforth the source version will match the shared-library minor
* and patch numbers; the shared-library major version number will be
* used for changes in backward compatibility, as it is intended.
* *
* BETA NOTICE: * BETA NOTICE:
* This is a beta version. It reads and writes valid files on the * This is a beta version. It reads and writes valid files on the
@ -94,12 +119,12 @@ extern "C" {
*/ */
/* Version information for png.h - this should match the version in png.c */ /* Version information for png.h - this should match the version in png.c */
#define PNG_LIBPNG_VER_STRING "0.97" #define PNG_LIBPNG_VER_STRING "0.98"
/* careful here. At one time, I wanted to use 082, but that would be octal. /* careful here. At one time, I wanted to use 082, but that would be octal.
* Version 1.0 will be 100 here, etc. * Version 1.0 will be 100 here, etc.
*/ */
#define PNG_LIBPNG_VER 97 #define PNG_LIBPNG_VER 98
/* variables declared in png.c - only it needs to define PNG_NO_EXTERN */ /* variables declared in png.c - only it needs to define PNG_NO_EXTERN */
#ifndef PNG_NO_EXTERN #ifndef PNG_NO_EXTERN
@ -108,33 +133,6 @@ extern "C" {
*/ */
extern char png_libpng_ver[]; extern char png_libpng_ver[];
/*
* Note about libpng version numbers:
*
* Due to various miscommunications, unforeseen code incompatibilities
* and occasional factors outside the authors' control, version numbering
* on the library has not always been consistent and straightforward.
* The following table summarizes matters since version 0.89c, which was
* the first widely used release:
*
* source png.h shared-lib
* version string version
* ------- ------ ----------
* 0.89c ("1.0 beta 3") 0.89 1.0.89
* 0.90 ("1.0 beta 4") 0.90 0.90 [should have been 2.0.90]
* 0.95 ("1.0 beta 5") 0.95 0.95 [should have been 2.0.95]
* 0.96 ("1.0 beta 6") 0.96 0.96 [should have been 2.0.96]
* 0.97b ("1.00.97 beta 7") 1.00.97 1.0.0 [should have been 2.0.97]
* 0.97c 0.97 2.0.97
* 0.98 0.98 2.0.98
* 0.99 0.99 2.0.99
* 1.0 1.00 2.1.0
*
* Henceforth the source version will match the shared-library minor
* and patch numbers; the shared-library major version number will be
* used for changes in backward compatibility, as it is intended.
*/
/* Structures to facilitate easy interlacing. See png.c for more details */ /* Structures to facilitate easy interlacing. See png.c for more details */
extern int FARDATA png_pass_start[]; extern int FARDATA png_pass_start[];
extern int FARDATA png_pass_inc[]; extern int FARDATA png_pass_inc[];
@ -584,7 +582,7 @@ struct png_struct_def
#if defined(PNG_READ_GAMMA_SUPPORTED) #if defined(PNG_READ_GAMMA_SUPPORTED)
int gamma_shift; /* number of "insignificant" bits 16-bit gamma */ int gamma_shift; /* number of "insignificant" bits 16-bit gamma */
float gamma; /* file gamma value */ float gamma; /* file gamma value */
float display_gamma; /* display gamma value */ float screen_gamma; /* screen gamma value (display_gamma/viewing_gamma */
#endif /* PNG_READ_GAMMA_SUPPORTED */ #endif /* PNG_READ_GAMMA_SUPPORTED */
#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
png_bytep gamma_table; /* gamma table for 8 bit depth files */ png_bytep gamma_table; /* gamma table for 8 bit depth files */
@ -626,6 +624,7 @@ struct png_struct_def
png_charp current_text; /* current text chunk buffer */ png_charp current_text; /* current text chunk buffer */
png_charp current_text_ptr; /* current location in current_text */ png_charp current_text_ptr; /* current location in current_text */
#endif /* PNG_PROGRESSIVE_READ_SUPPORTED && PNG_READ_tEXt/zTXt_SUPPORTED */ #endif /* PNG_PROGRESSIVE_READ_SUPPORTED && PNG_READ_tEXt/zTXt_SUPPORTED */
#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__) #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
/* for the Borland special 64K segment handler */ /* for the Borland special 64K segment handler */
png_bytepp offset_table_ptr; png_bytepp offset_table_ptr;
@ -633,8 +632,7 @@ struct png_struct_def
png_uint_16 offset_table_number; png_uint_16 offset_table_number;
png_uint_16 offset_table_count; png_uint_16 offset_table_count;
png_uint_16 offset_table_count_free; png_uint_16 offset_table_count_free;
#endif /* PNG_PROGRESSIVE_READ_SUPPORTED&&__TURBOC__&&!_Windows&&!__FLAT__ */ #endif /* __TURBOC__&&!_Windows&&!__FLAT__ */
#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
#if defined(PNG_READ_DITHER_SUPPORTED) #if defined(PNG_READ_DITHER_SUPPORTED)
png_bytep palette_lookup; /* lookup table for dithering */ png_bytep palette_lookup; /* lookup table for dithering */
png_bytep dither_index; /* index translation for palette files */ png_bytep dither_index; /* index translation for palette files */
@ -649,9 +647,9 @@ struct png_struct_def
png_uint_16p filter_costs; /* relative filter calculation cost */ png_uint_16p filter_costs; /* relative filter calculation cost */
png_uint_16p inv_filter_costs; /* 1/relative filter calculation cost */ png_uint_16p inv_filter_costs; /* 1/relative filter calculation cost */
#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */ #endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
#if defined(PNG_TIME_RFC1152_SUPPORTED) #if defined(PNG_TIME_RFC1123_SUPPORTED)
png_charp time_buffer; /* String to hold RFC 1152 time text */ png_charp time_buffer; /* String to hold RFC 1123 time text */
#endif /* PNG_TIME_RFC1152_SUPPORTED */ #endif /* PNG_TIME_RFC1123_SUPPORTED */
}; };
typedef png_struct FAR * FAR * png_structpp; typedef png_struct FAR * FAR * png_structpp;
@ -706,10 +704,10 @@ extern PNG_EXPORT(void,png_write_info) PNGARG((png_structp png_ptr,
extern PNG_EXPORT(void,png_read_info) PNGARG((png_structp png_ptr, extern PNG_EXPORT(void,png_read_info) PNGARG((png_structp png_ptr,
png_infop info_ptr)); png_infop info_ptr));
#if defined(PNG_TIME_RFC1152_SUPPORTED) #if defined(PNG_TIME_RFC1123_SUPPORTED)
extern PNG_EXPORT(png_charp,png_convert_to_rfc1152) extern PNG_EXPORT(png_charp,png_convert_to_rfc1123)
PNGARG((png_structp png_ptr, png_timep ptime)); PNGARG((png_structp png_ptr, png_timep ptime));
#endif /* PNG_TIME_RFC1152_SUPPORTED */ #endif /* PNG_TIME_RFC1123_SUPPORTED */
#if defined(PNG_WRITE_tIME_SUPPORTED) #if defined(PNG_WRITE_tIME_SUPPORTED)
/* convert from a struct tm to png_time */ /* convert from a struct tm to png_time */
@ -753,6 +751,11 @@ extern PNG_EXPORT(void,png_set_strip_alpha) PNGARG((png_structp png_ptr));
extern PNG_EXPORT(void,png_set_swap_alpha) PNGARG((png_structp png_ptr)); extern PNG_EXPORT(void,png_set_swap_alpha) PNGARG((png_structp png_ptr));
#endif /* PNG_READ_SWAP_ALPHA_SUPPORTED || PNG_WRITE_SWAP_ALPHA_SUPPORTED */ #endif /* PNG_READ_SWAP_ALPHA_SUPPORTED || PNG_WRITE_SWAP_ALPHA_SUPPORTED */
#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
extern PNG_EXPORT(void,png_set_invert_alpha) PNGARG((png_structp png_ptr));
#endif /* PNG_READ_INVERT_ALPHA_SUPPORTED || PNG_WRITE_INVERT_ALPHA_SUPPORTED */
#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
/* Add a filler byte to 24-bit RGB images. */ /* Add a filler byte to 24-bit RGB images. */
extern PNG_EXPORT(void,png_set_filler) PNGARG((png_structp png_ptr, extern PNG_EXPORT(void,png_set_filler) PNGARG((png_structp png_ptr,
@ -819,7 +822,7 @@ extern PNG_EXPORT(void,png_set_dither) PNGARG((png_structp png_ptr,
#endif /* PNG_READ_DITHER_SUPPORTED */ #endif /* PNG_READ_DITHER_SUPPORTED */
#if defined(PNG_READ_GAMMA_SUPPORTED) #if defined(PNG_READ_GAMMA_SUPPORTED)
/* Handle gamma correction. */ /* Handle gamma correction. Screen_gamma=(display_gamma/viewing_gamma) */
extern PNG_EXPORT(void,png_set_gamma) PNGARG((png_structp png_ptr, extern PNG_EXPORT(void,png_set_gamma) PNGARG((png_structp png_ptr,
double screen_gamma, double default_file_gamma)); double screen_gamma, double default_file_gamma));
#endif /* PNG_READ_GAMMA_SUPPORTED */ #endif /* PNG_READ_GAMMA_SUPPORTED */
@ -1240,14 +1243,14 @@ extern PNG_EXPORT(void,png_set_sBIT) PNGARG((png_structp png_ptr,
#if defined(PNG_READ_sRGB_SUPPORTED) #if defined(PNG_READ_sRGB_SUPPORTED)
extern PNG_EXPORT(png_uint_32,png_get_sRGB) PNGARG((png_structp png_ptr, extern PNG_EXPORT(png_uint_32,png_get_sRGB) PNGARG((png_structp png_ptr,
png_infop info_ptr, png_bytep srgb_intent)); png_infop info_ptr, int *intent));
#endif /* PNG_READ_sRGB_SUPPORTED */ #endif /* PNG_READ_sRGB_SUPPORTED */
#if defined(PNG_READ_sRGB_SUPPORTED) || defined(PNG_WRITE_sRGB_SUPPORTED) #if defined(PNG_READ_sRGB_SUPPORTED) || defined(PNG_WRITE_sRGB_SUPPORTED)
extern PNG_EXPORT(void,png_set_sRGB) PNGARG((png_structp png_ptr, extern PNG_EXPORT(void,png_set_sRGB) PNGARG((png_structp png_ptr,
png_infop info_ptr, png_byte srgb_intent)); png_infop info_ptr, int intent));
extern PNG_EXPORT(void,png_set_sRGB_gAMA_and_cHRM) PNGARG((png_structp png_ptr, extern PNG_EXPORT(void,png_set_sRGB_gAMA_and_cHRM) PNGARG((png_structp png_ptr,
png_infop info_ptr, png_byte srgb_intent)); png_infop info_ptr, int intent));
#endif /* PNG_READ_sRGB_SUPPORTED || PNG_WRITE_sRGB_SUPPORTED */ #endif /* PNG_READ_sRGB_SUPPORTED || PNG_WRITE_sRGB_SUPPORTED */
#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED) #if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED)
@ -1361,6 +1364,7 @@ extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr,
#define PNG_PACKSWAP 0x10000 #define PNG_PACKSWAP 0x10000
#define PNG_SWAP_ALPHA 0x20000 #define PNG_SWAP_ALPHA 0x20000
#define PNG_STRIP_ALPHA 0x40000 #define PNG_STRIP_ALPHA 0x40000
#define PNG_INVERT_ALPHA 0x80000
/* flags for png_create_struct */ /* flags for png_create_struct */
#define PNG_STRUCT_PNG 0x0001 #define PNG_STRUCT_PNG 0x0001
@ -1585,7 +1589,7 @@ PNG_EXTERN void png_write_cHRM PNGARG((png_structp png_ptr,
#if defined(PNG_WRITE_sRGB_SUPPORTED) #if defined(PNG_WRITE_sRGB_SUPPORTED)
PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr, PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr,
png_byte srgb_intent)); int intent));
#endif #endif
#if defined(PNG_WRITE_tRNS_SUPPORTED) #if defined(PNG_WRITE_tRNS_SUPPORTED)
@ -1702,6 +1706,16 @@ PNG_EXTERN void png_do_write_swap_alpha PNGARG((png_row_infop row_info,
png_bytep row)); png_bytep row));
#endif #endif
#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
PNG_EXTERN void png_do_read_invert_alpha PNGARG((png_row_infop row_info,
png_bytep row));
#endif
#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info,
png_bytep row));
#endif
#if defined(PNG_WRITE_FILLER_SUPPORTED) || \ #if defined(PNG_WRITE_FILLER_SUPPORTED) || \
defined(PNG_READ_STRIP_ALPHA_SUPPORTED) defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
PNG_EXTERN void png_do_strip_filler PNGARG((png_row_infop row_info, PNG_EXTERN void png_do_strip_filler PNGARG((png_row_infop row_info,

38
pngconf.h
View File

@ -1,12 +1,12 @@
/* pngconf.c - machine configurable file for libpng /* pngconf.c - machine configurable file for libpng
* *
* libpng 0.97 * libpng 0.98
* For conditions of distribution and use, see copyright notice in png.h * For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
* Copyright (c) 1996, 1997 Andreas Dilger * Copyright (c) 1996, 1997 Andreas Dilger
* Copyright (c) 1998, Glenn Randers-Pehrson * Copyright (c) 1998, Glenn Randers-Pehrson
* January 7, 1998 * January 16, 1998
*/ */
/* Any machine specific code is near the front of this file, so if you /* Any machine specific code is near the front of this file, so if you
@ -191,24 +191,25 @@ __dont__ include it again
* less then 8, and even that may not work (I haven't tested it). * less then 8, and even that may not work (I haven't tested it).
*/ */
#ifndef PNG_MAX_GAMMA_8
#define PNG_MAX_GAMMA_8 11 #define PNG_MAX_GAMMA_8 11
#endif
/* This controls how much a difference in gamma we can tolerate before /* This controls how much a difference in gamma we can tolerate before
* we actually start doing gamma conversion. * we actually start doing gamma conversion.
*/ */
#ifndef PNG_GAMMA_THRESHOLD
#define PNG_GAMMA_THRESHOLD 0.05 #define PNG_GAMMA_THRESHOLD 0.05
#endif
#endif /* PNG_INTERNAL */ #endif /* PNG_INTERNAL */
/* The following uses const char * instead of char * for error /* The following uses const char * instead of char * for error
* and warning message functions, so some compilers won't complain. * and warning message functions, so some compilers won't complain.
* If you want to use const, define PNG_USE_CONST here. It is not * If you do not want to use const, define PNG_NO_CONST here.
* normally defined to make configuration easier, as it is not a
* critical part of the code.
*/ */
#define PNG_USE_CONST
#ifdef PNG_USE_CONST #ifndef PNG_NO_CONST
# define PNG_CONST const # define PNG_CONST const
#else #else
# define PNG_CONST # define PNG_CONST
@ -259,6 +260,7 @@ __dont__ include it again
#define PNG_READ_GAMMA_SUPPORTED #define PNG_READ_GAMMA_SUPPORTED
#define PNG_READ_GRAY_TO_RGB_SUPPORTED #define PNG_READ_GRAY_TO_RGB_SUPPORTED
#define PNG_READ_SWAP_ALPHA_SUPPORTED #define PNG_READ_SWAP_ALPHA_SUPPORTED
#define PNG_READ_INVERT_ALPHA_SUPPORTED
#define PNG_READ_STRIP_ALPHA_SUPPORTED #define PNG_READ_STRIP_ALPHA_SUPPORTED
#define PNG_READ_COMPOSITE_NODIV_SUPPORTED /* well tested on Intel */ #define PNG_READ_COMPOSITE_NODIV_SUPPORTED /* well tested on Intel */
#endif /* PNG_READ_FULLY_SUPPORTED */ #endif /* PNG_READ_FULLY_SUPPORTED */
@ -275,22 +277,32 @@ __dont__ include it again
#define PNG_WRITE_FILLER_SUPPORTED /* This is the same as WRITE_STRIP_ALPHA */ #define PNG_WRITE_FILLER_SUPPORTED /* This is the same as WRITE_STRIP_ALPHA */
#define PNG_WRITE_FLUSH_SUPPORTED #define PNG_WRITE_FLUSH_SUPPORTED
#define PNG_WRITE_SWAP_ALPHA_SUPPORTED #define PNG_WRITE_SWAP_ALPHA_SUPPORTED
#define PNG_WRITE_INVERT_ALPHA_SUPPORTED
#define PNG_WRITE_WEIGHTED_FILTER_SUPPORTED #define PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
#endif /* PNG_WRITE_FULLY_SUPPORTED */ #endif /* PNG_WRITE_FULLY_SUPPORTED */
#if !defined(PNG_NO_STDIO) #if !defined(PNG_NO_STDIO)
#define PNG_TIME_RFC1152_SUPPORTED #define PNG_TIME_RFC1123_SUPPORTED
#endif #endif
/* These are currently experimental features */ /* These are currently experimental features, define them if you want */
#undef PNG_READ_16_TO_8_ACCURATE_SHIFT_SUPPORTED /* very little testing */
/* very little testing */
/*
#define PNG_READ_16_TO_8_ACCURATE_SHIFT_SUPPORTED
*/
/* This is only for PowerPC big-endian and 680x0 systems */ /* This is only for PowerPC big-endian and 680x0 systems */
#undef PNG_READ_BIG_ENDIAN_SUPPORTED /* some testing */ /* some testing */
/*
#define PNG_READ_BIG_ENDIAN_SUPPORTED
*/
/* These functions are turned off by default, as they will be phased out. */ /* These functions are turned off by default, as they will be phased out. */
#undef PNG_USELESS_TESTS_SUPPORTED /*
#undef PNG_CORRECT_PALETTE_SUPPORTED #define PNG_USELESS_TESTS_SUPPORTED
#define PNG_CORRECT_PALETTE_SUPPORTED
*/
/* Any chunks you are not interested in, you can undef here. The /* Any chunks you are not interested in, you can undef here. The
* ones that allocate memory may be expecially important (hIST, * ones that allocate memory may be expecially important (hIST,

4
pngerror.c
View File

@ -1,12 +1,12 @@
/* pngerror.c - stub functions for i/o and memory allocation /* pngerror.c - stub functions for i/o and memory allocation
* *
* libpng 0.97 * libpng 0.98
* For conditions of distribution and use, see copyright notice in png.h * For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
* Copyright (c) 1996, 1997 Andreas Dilger * Copyright (c) 1996, 1997 Andreas Dilger
* Copyright (c) 1998, Glenn Randers-Pehrson * Copyright (c) 1998, Glenn Randers-Pehrson
* January 7, 1998 * January 16, 1998
* *
* This file provides a location for all error handling. Users which * This file provides a location for all error handling. Users which
* need special error handling are expected to write replacement functions * need special error handling are expected to write replacement functions

12
pngget.c
View File

@ -1,12 +1,12 @@
/* pngget.c - retrieval of values from info struct /* pngget.c - retrieval of values from info struct
* *
* libpng 0.97 * libpng 0.98
* For conditions of distribution and use, see copyright notice in png.h * For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
* Copyright (c) 1996, 1997 Andreas Dilger * Copyright (c) 1996, 1997 Andreas Dilger
* Copyright (c) 1998, Glenn Randers-Pehrson * Copyright (c) 1998, Glenn Randers-Pehrson
* January 7, 1998 * January 16, 1998
*/ */
#define PNG_INTERNAL #define PNG_INTERNAL
@ -112,14 +112,13 @@ png_get_gAMA(png_structp png_ptr, png_infop info_ptr, double *file_gamma)
#if defined(PNG_READ_sRGB_SUPPORTED) #if defined(PNG_READ_sRGB_SUPPORTED)
png_uint_32 png_uint_32
png_get_sRGB(png_structp png_ptr, png_infop info_ptr, png_bytep png_get_sRGB(png_structp png_ptr, png_infop info_ptr, int *file_srgb_intent)
file_srgb_intent)
{ {
if (info_ptr != NULL && info_ptr->valid & PNG_INFO_sRGB && if (info_ptr != NULL && info_ptr->valid & PNG_INFO_sRGB &&
file_srgb_intent != NULL) file_srgb_intent != NULL)
{ {
png_debug1(1, "in %s retrieval function\n", "sRGB"); png_debug1(1, "in %s retrieval function\n", "sRGB");
*file_srgb_intent = info_ptr->srgb_intent; *file_srgb_intent = (int)info_ptr->srgb_intent;
return (PNG_INFO_sRGB); return (PNG_INFO_sRGB);
} }
return (0); return (0);
@ -272,7 +271,8 @@ png_get_text(png_structp png_ptr, png_infop info_ptr, png_textp *text_ptr,
if ((info_ptr != NULL) || (info_ptr->num_text > 0)) if ((info_ptr != NULL) || (info_ptr->num_text > 0))
{ {
png_debug1(1, "in %s retrieval function\n", png_debug1(1, "in %s retrieval function\n",
(png_ptr->chunk_name[0] == '\0' ? "text" : png_ptr->chunk_name)); (png_ptr->chunk_name[0] == '\0' ? "text"
: (png_const_charp)png_ptr->chunk_name));
if (text_ptr != NULL) if (text_ptr != NULL)
*text_ptr = info_ptr->text; *text_ptr = info_ptr->text;
if (num_text != NULL) if (num_text != NULL)

27
pngmem.c
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@ -1,12 +1,11 @@
/* pngmem.c - stub functions for memory allocation /* pngmem.c - stub functions for memory allocation
* *
* libpng 0.97 * libpng 0.98
* For conditions of distribution and use, see copyright notice in png.h * For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
* Copyright (c) 1996, 1997 Andreas Dilger * Copyright (c) 1996, 1997 Andreas Dilger
* Copyright (c) 1998, Glenn Randers-Pehrson * Copyright (c) 1998, Glenn Randers-Pehrson
* January 7, 1998 * January 16, 1998
* *
* This file provides a location for all memory allocation. Users which * This file provides a location for all memory allocation. Users which
* need special memory handling are expected to modify the code in this file * need special memory handling are expected to modify the code in this file
@ -16,6 +15,16 @@
#define PNG_INTERNAL #define PNG_INTERNAL
#include "png.h" #include "png.h"
/* The following "hides" PNG_MALLOC and PNG_FREE thus allowing the pngtest
application to put a wrapper on top of them. */
#ifdef PNGTEST_MEMORY_DEBUG
#define PNG_MALLOC png_debug_malloc
#define PNG_FREE png_debug_free
#else
#define PNG_MALLOC png_malloc
#define PNG_FREE png_free
#endif
/* Borland DOS special memory handler */ /* Borland DOS special memory handler */
#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__) #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
/* if you change this, be sure to change the one in png.h also */ /* if you change this, be sure to change the one in png.h also */
@ -72,7 +81,7 @@ png_destroy_struct(png_voidp struct_ptr)
* (which should cause a fatal error) and introducing major problems. * (which should cause a fatal error) and introducing major problems.
*/ */
png_voidp png_voidp
png_malloc(png_structp png_ptr, png_uint_32 size) PNG_MALLOC(png_structp png_ptr, png_uint_32 size)
{ {
png_voidp ret; png_voidp ret;
if (png_ptr == NULL || size == 0) if (png_ptr == NULL || size == 0)
@ -166,11 +175,11 @@ png_malloc(png_structp png_ptr, png_uint_32 size)
return ret; return ret;
} }
/* free a pointer allocated by png_malloc(). In the default /* free a pointer allocated by PNG_MALLOC(). In the default
configuration, png_ptr is not used, but is passed in case it configuration, png_ptr is not used, but is passed in case it
is needed. If ptr is NULL, return without taking any action. */ is needed. If ptr is NULL, return without taking any action. */
void void
png_free(png_structp png_ptr, png_voidp ptr) PNG_FREE(png_structp png_ptr, png_voidp ptr)
{ {
if (png_ptr == NULL || ptr == NULL) if (png_ptr == NULL || ptr == NULL)
return; return;
@ -260,7 +269,7 @@ png_destroy_struct(png_voidp struct_ptr)
have the ability to do that. */ have the ability to do that. */
png_voidp png_voidp
png_malloc(png_structp png_ptr, png_uint_32 size) PNG_MALLOC(png_structp png_ptr, png_uint_32 size)
{ {
png_voidp ret; png_voidp ret;
if (png_ptr == NULL || size == 0) if (png_ptr == NULL || size == 0)
@ -289,11 +298,11 @@ png_malloc(png_structp png_ptr, png_uint_32 size)
return ret; return ret;
} }
/* Free a pointer allocated by png_malloc(). In the default /* Free a pointer allocated by PNG_MALLOC(). In the default
configuration, png_ptr is not used, but is passed in case it configuration, png_ptr is not used, but is passed in case it
is needed. If ptr is NULL, return without taking any action. */ is needed. If ptr is NULL, return without taking any action. */
void void
png_free(png_structp png_ptr, png_voidp ptr) PNG_FREE(png_structp png_ptr, png_voidp ptr)
{ {
if (png_ptr == NULL || ptr == NULL) if (png_ptr == NULL || ptr == NULL)
return; return;

4
pngpread.c
View File

@ -1,12 +1,12 @@
/* pngpread.c - read a png file in push mode /* pngpread.c - read a png file in push mode
* *
* libpng 0.97 * libpng 0.98
* For conditions of distribution and use, see copyright notice in png.h * For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
* Copyright (c) 1996, 1997 Andreas Dilger * Copyright (c) 1996, 1997 Andreas Dilger
* Copyright (c) 1998, Glenn Randers-Pehrson * Copyright (c) 1998, Glenn Randers-Pehrson
* January 7, 1998 * January 16, 1998
*/ */
#define PNG_INTERNAL #define PNG_INTERNAL

10
pngread.c
View File

@ -1,12 +1,12 @@
/* pngread.c - read a PNG file /* pngread.c - read a PNG file
* *
* libpng 0.97 * libpng 0.98
* For conditions of distribution and use, see copyright notice in png.h * For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
* Copyright (c) 1996, 1997 Andreas Dilger * Copyright (c) 1996, 1997 Andreas Dilger
* Copyright (c) 1998, Glenn Randers-Pehrson * Copyright (c) 1998, Glenn Randers-Pehrson
* January 7, 1998 * January 16, 1998
* *
* This file contains routines that an application calls directly to * This file contains routines that an application calls directly to
* read a PNG file or stream. * read a PNG file or stream.
@ -655,12 +655,18 @@ png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
if (info_ptr != NULL) if (info_ptr != NULL)
{ {
#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED)
png_free(png_ptr, info_ptr->text);
#endif
png_destroy_struct((png_voidp)info_ptr); png_destroy_struct((png_voidp)info_ptr);
*info_ptr_ptr = (png_infop)NULL; *info_ptr_ptr = (png_infop)NULL;
} }
if (end_info_ptr != NULL) if (end_info_ptr != NULL)
{ {
#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED)
png_free(png_ptr, info_ptr->text);
#endif
png_destroy_struct((png_voidp)end_info_ptr); png_destroy_struct((png_voidp)end_info_ptr);
*end_info_ptr_ptr = (png_infop)NULL; *end_info_ptr_ptr = (png_infop)NULL;
} }

4
pngrio.c
View File

@ -1,12 +1,12 @@
/* pngrio.c - functions for data input /* pngrio.c - functions for data input
* *
* libpng 0.97 * libpng 0.98
* For conditions of distribution and use, see copyright notice in png.h * For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
* Copyright (c) 1996, 1997 Andreas Dilger * Copyright (c) 1996, 1997 Andreas Dilger
* Copyright (c) 1998, Glenn Randers-Pehrson * Copyright (c) 1998, Glenn Randers-Pehrson
* January 7, 1998 * January 16, 1998
* *
* This file provides a location for all input. Users which need * This file provides a location for all input. Users which need
* special handling are expected to write a function which has the same * special handling are expected to write a function which has the same

134
pngrtran.c
View File

@ -1,12 +1,12 @@
/* pngrtran.c - transforms the data in a row for PNG readers /* pngrtran.c - transforms the data in a row for PNG readers
* *
* libpng 0.97 * libpng 0.98
* For conditions of distribution and use, see copyright notice in png.h * For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
* Copyright (c) 1996, 1997 Andreas Dilger * Copyright (c) 1996, 1997 Andreas Dilger
* Copyright (c) 1998, Glenn Randers-Pehrson * Copyright (c) 1998, Glenn Randers-Pehrson
* January 7, 1998 * January 16, 1998
* *
* This file contains functions optionally called by an application * This file contains functions optionally called by an application
* in order to tell libpng how to handle data when reading a PNG. * in order to tell libpng how to handle data when reading a PNG.
@ -549,13 +549,13 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
* also needlessly introduces small errors. * also needlessly introduces small errors.
*/ */
void void
png_set_gamma(png_structp png_ptr, double screen_gamma, double file_gamma) png_set_gamma(png_structp png_ptr, double scrn_gamma, double file_gamma)
{ {
png_debug(1, "in png_set_gamma\n"); png_debug(1, "in png_set_gamma\n");
if (fabs(screen_gamma * file_gamma - 1.0) > PNG_GAMMA_THRESHOLD) if (fabs(scrn_gamma * file_gamma - 1.0) > PNG_GAMMA_THRESHOLD)
png_ptr->transformations |= PNG_GAMMA; png_ptr->transformations |= PNG_GAMMA;
png_ptr->gamma = (float)file_gamma; png_ptr->gamma = (float)file_gamma;
png_ptr->display_gamma = (float)screen_gamma; png_ptr->screen_gamma = (float)scrn_gamma;
} }
#endif #endif
@ -592,6 +592,7 @@ png_set_rgb_to_gray(png_structp png_ptr, int gray_bits)
png_debug(1, "in png_set_rgb_to_gray\n"); png_debug(1, "in png_set_rgb_to_gray\n");
png_ptr->transformations |= PNG_RGB_TO_GRAY; png_ptr->transformations |= PNG_RGB_TO_GRAY;
/* Need to do something with gray_bits here. */ /* Need to do something with gray_bits here. */
png_warning(png_ptr, "RGB to GRAY transformation is not yet implemented.");
} }
#endif #endif
@ -644,6 +645,23 @@ png_init_read_transformations(png_structp png_ptr)
png_ptr->palette[png_ptr->background.index].green; png_ptr->palette[png_ptr->background.index].green;
png_ptr->background.blue = png_ptr->background.blue =
png_ptr->palette[png_ptr->background.index].blue; png_ptr->palette[png_ptr->background.index].blue;
#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
if (png_ptr->transformations & PNG_INVERT_ALPHA)
{
#if defined(PNG_READ_EXPAND_SUPPORTED)
if (png_ptr->transformations & !PNG_EXPAND)
#endif
{
/* invert the alpha channel (in tRNS) unless the pixels are
going to be expanded, in which case leave it for later */
int i;
for (i=0; i<png_ptr->num_trans; i++)
png_ptr->trans[i] = 255 - png_ptr->trans[i];
}
}
#endif
} }
} }
#endif #endif
@ -681,7 +699,7 @@ png_init_read_transformations(png_structp png_ptr)
{ {
double g; double g;
g = 1.0 / (png_ptr->background_gamma * png_ptr->display_gamma); g = 1.0 / (png_ptr->background_gamma * png_ptr->screen_gamma);
if (png_ptr->background_gamma_type==PNG_BACKGROUND_GAMMA_SCREEN|| if (png_ptr->background_gamma_type==PNG_BACKGROUND_GAMMA_SCREEN||
fabs(g - 1.0) < PNG_GAMMA_THRESHOLD) fabs(g - 1.0) < PNG_GAMMA_THRESHOLD)
@ -761,17 +779,17 @@ png_init_read_transformations(png_structp png_ptr)
switch (png_ptr->background_gamma_type) switch (png_ptr->background_gamma_type)
{ {
case PNG_BACKGROUND_GAMMA_SCREEN: case PNG_BACKGROUND_GAMMA_SCREEN:
g = (png_ptr->display_gamma); g = (png_ptr->screen_gamma);
gs = 1.0; gs = 1.0;
break; break;
case PNG_BACKGROUND_GAMMA_FILE: case PNG_BACKGROUND_GAMMA_FILE:
g = 1.0 / (png_ptr->gamma); g = 1.0 / (png_ptr->gamma);
gs = 1.0 / (png_ptr->gamma * png_ptr->display_gamma); gs = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
break; break;
case PNG_BACKGROUND_GAMMA_UNIQUE: case PNG_BACKGROUND_GAMMA_UNIQUE:
g = 1.0 / (png_ptr->background_gamma); g = 1.0 / (png_ptr->background_gamma);
gs = 1.0 / (png_ptr->background_gamma * gs = 1.0 / (png_ptr->background_gamma *
png_ptr->display_gamma); png_ptr->screen_gamma);
break; break;
} }
@ -954,7 +972,7 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
else else
info_ptr->channels = 1; info_ptr->channels = 1;
#if defined(PNG_STRIP_ALPHA_SUPPORTED) #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
if ((png_ptr->transformations & PNG_STRIP_ALPHA) && if ((png_ptr->transformations & PNG_STRIP_ALPHA) &&
info_ptr->color_type & PNG_COLOR_MASK_ALPHA) info_ptr->color_type & PNG_COLOR_MASK_ALPHA)
{ {
@ -1112,6 +1130,11 @@ png_do_read_transformations(png_structp png_ptr)
png_do_read_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); png_do_read_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);
#endif #endif
#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
if (png_ptr->transformations & PNG_INVERT_ALPHA)
png_do_read_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);
#endif
#if defined(PNG_READ_SWAP_SUPPORTED) #if defined(PNG_READ_SWAP_SUPPORTED)
if (png_ptr->transformations & PNG_SWAP_BYTES) if (png_ptr->transformations & PNG_SWAP_BYTES)
png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1); png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1);
@ -1468,6 +1491,87 @@ png_do_read_swap_alpha(png_row_infop row_info, png_bytep row)
} }
#endif #endif
#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
void
png_do_read_invert_alpha(png_row_infop row_info, png_bytep row)
{
png_debug(1, "in png_do_read_invert_alpha\n");
#if defined(PNG_USELESS_TESTS_SUPPORTED)
if (row != NULL && row_info != NULL)
#endif
{
if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
{
/* This inverts the alpha channel in RGBA */
if (row_info->bit_depth == 8)
{
png_bytep sp, dp;
png_uint_32 i;
for (i = 0, sp = dp = row + row_info->rowbytes;
i < row_info->width; i++)
{
*(--dp) = *(--sp);
*(--dp) = *(--sp);
*(--dp) = *(--sp);
*(--dp) = 255 - *(--sp);
}
}
/* This inverts the alpha channel in RRGGBBAA */
else
{
png_bytep sp, dp;
png_uint_32 i;
for (i = 0, sp = dp = row + row_info->rowbytes;
i < row_info->width; i++)
{
*(--dp) = *(--sp);
*(--dp) = *(--sp);
*(--dp) = *(--sp);
*(--dp) = *(--sp);
*(--dp) = *(--sp);
*(--dp) = *(--sp);
*(--dp) = 255 - *(--sp);
*(--dp) = 255 - *(--sp);
}
}
}
else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
{
/* This inverts the alpha channel in AG */
if (row_info->bit_depth == 8)
{
png_bytep sp, dp;
png_uint_32 i;
for (i = 0, sp = dp = row + row_info->rowbytes;
i < row_info->width; i++)
{
*(--dp) = *(--sp);
*(--dp) = 255 - *(--sp);
}
}
/* This inverts the alpha channel in AAGG */
else
{
png_bytep sp, dp;
png_uint_32 i;
for (i = 0, sp = dp = row + row_info->rowbytes;
i < row_info->width; i++)
{
*(--dp) = *(--sp);
*(--dp) = *(--sp);
*(--dp) = 255 - *(--sp);
*(--dp) = 255 - *(--sp);
}
}
}
}
}
#endif
#if defined(PNG_READ_FILLER_SUPPORTED) #if defined(PNG_READ_FILLER_SUPPORTED)
/* Add filler channel if we have RGB color */ /* Add filler channel if we have RGB color */
void void
@ -1693,7 +1797,7 @@ png_correct_palette(png_structp png_ptr, png_colorp palette,
{ {
double g; double g;
g = 1.0 / (png_ptr->background_gamma * png_ptr->display_gamma); g = 1.0 / (png_ptr->background_gamma * png_ptr->screen_gamma);
if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_SCREEN || if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_SCREEN ||
fabs(g - 1.0) < PNG_GAMMA_THRESHOLD) fabs(g - 1.0) < PNG_GAMMA_THRESHOLD)
@ -3082,7 +3186,7 @@ png_build_gamma_table(png_structp png_ptr)
int i; int i;
double g; double g;
g = 1.0 / (png_ptr->gamma * png_ptr->display_gamma); g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
png_ptr->gamma_table = (png_bytep)png_malloc(png_ptr, png_ptr->gamma_table = (png_bytep)png_malloc(png_ptr,
(png_uint_32)256); (png_uint_32)256);
@ -3107,7 +3211,7 @@ png_build_gamma_table(png_structp png_ptr)
g) * 255.0 + .5); g) * 255.0 + .5);
} }
g = 1.0 / (png_ptr->display_gamma); g = 1.0 / (png_ptr->screen_gamma);
png_ptr->gamma_from_1 = (png_bytep)png_malloc(png_ptr, png_ptr->gamma_from_1 = (png_bytep)png_malloc(png_ptr,
(png_uint_32)256); (png_uint_32)256);
@ -3160,7 +3264,7 @@ png_build_gamma_table(png_structp png_ptr)
num = (1 << (8 - shift)); num = (1 << (8 - shift));
g = 1.0 / (png_ptr->gamma * png_ptr->display_gamma); g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
png_ptr->gamma_16_table = (png_uint_16pp)png_malloc(png_ptr, png_ptr->gamma_16_table = (png_uint_16pp)png_malloc(png_ptr,
num * sizeof (png_uint_16p)); num * sizeof (png_uint_16p));
@ -3238,7 +3342,7 @@ png_build_gamma_table(png_structp png_ptr)
65535.0, g) * 65535.0 + .5); 65535.0, g) * 65535.0 + .5);
} }
} }
g = 1.0 / (png_ptr->display_gamma); g = 1.0 / (png_ptr->screen_gamma);
png_ptr->gamma_16_from_1 = (png_uint_16pp)png_malloc(png_ptr, png_ptr->gamma_16_from_1 = (png_uint_16pp)png_malloc(png_ptr,
num * sizeof (png_uint_16p)); num * sizeof (png_uint_16p));

16
pngrutil.c
View File

@ -1,12 +1,12 @@
/* pngrutil.c - utilities to read a PNG file /* pngrutil.c - utilities to read a PNG file
* *
* libpng 0.97 * libpng 0.98
* For conditions of distribution and use, see copyright notice in png.h * For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
* Copyright (c) 1996, 1997 Andreas Dilger * Copyright (c) 1996, 1997 Andreas Dilger
* Copyright (c) 1998, Glenn Randers-Pehrson * Copyright (c) 1998, Glenn Randers-Pehrson
* January 7, 1998 * January 16, 1998
* *
* This file contains routines which are only called from within * This file contains routines which are only called from within
* libpng itself during the course of reading an image. * libpng itself during the course of reading an image.
@ -106,7 +106,7 @@ png_crc_finish(png_structp png_ptr, png_uint_32 skip)
return 0; return 0;
} }
/* Compare the CRC stored in the PNG file with that calulated by libpng from /* Compare the CRC stored in the PNG file with that calculated by libpng from
the data it has read thus far. */ the data it has read thus far. */
int int
png_crc_error(png_structp png_ptr) png_crc_error(png_structp png_ptr)
@ -281,7 +281,7 @@ png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
} }
num = (int)length / 3; num = (int)length / 3;
palette = (png_colorp)png_zalloc(png_ptr, num, sizeof (png_color)); palette = (png_colorp)png_zalloc(png_ptr, (uInt)num, sizeof (png_color));
png_ptr->flags |= PNG_FLAG_FREE_PALETTE; png_ptr->flags |= PNG_FLAG_FREE_PALETTE;
for (i = 0; i < num; i++) for (i = 0; i < num; i++)
{ {
@ -318,7 +318,7 @@ png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
{ {
png_chunk_warning(png_ptr, "CRC error"); png_chunk_warning(png_ptr, "CRC error");
png_ptr->flags &= ~PNG_FLAG_FREE_PALETTE; png_ptr->flags &= ~PNG_FLAG_FREE_PALETTE;
png_free(png_ptr, palette); png_zfree(png_ptr, palette);
return; return;
} }
} }
@ -404,7 +404,7 @@ png_handle_gAMA(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
#if defined(PNG_READ_sRGB_SUPPORTED) #if defined(PNG_READ_sRGB_SUPPORTED)
if (info_ptr->valid & PNG_INFO_sRGB) if (info_ptr->valid & PNG_INFO_sRGB)
if(igamma != (png_uint_32)45000L) if(igamma != (png_uint_32)51000L)
{ {
png_warning(png_ptr, png_warning(png_ptr,
"Ignoring incorrect gAMA value when sRGB is also present"); "Ignoring incorrect gAMA value when sRGB is also present");
@ -626,7 +626,7 @@ png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
void void
png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
{ {
png_byte intent; int intent;
png_byte buf[1]; png_byte buf[1];
png_debug(1, "in png_handle_sRGB\n"); png_debug(1, "in png_handle_sRGB\n");
@ -671,7 +671,7 @@ png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length)
#ifdef PNG_READ_gAMA_SUPPORTED #ifdef PNG_READ_gAMA_SUPPORTED
if ((info_ptr->valid & PNG_INFO_gAMA)) if ((info_ptr->valid & PNG_INFO_gAMA))
if((png_uint_32)(png_ptr->gamma*(float)100000.+.5) != (png_uint_32)45000L) if((png_uint_32)(png_ptr->gamma*(float)100000.+.5) != (png_uint_32)51000L)
{ {
png_warning(png_ptr, png_warning(png_ptr,
"Ignoring incorrect gAMA value when sRGB is also present"); "Ignoring incorrect gAMA value when sRGB is also present");

16
pngset.c
View File

@ -1,12 +1,12 @@
/* pngset.c - storage of image information into info struct /* pngset.c - storage of image information into info struct
* *
* libpng 0.97 * libpng 0.98
* For conditions of distribution and use, see copyright notice in png.h * For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
* Copyright (c) 1996, 1997 Andreas Dilger * Copyright (c) 1996, 1997 Andreas Dilger
* Copyright (c) 1998, Glenn Randers-Pehrson * Copyright (c) 1998, Glenn Randers-Pehrson
* January 7, 1998 * January 16, 1998
* *
* The functions here are used during reads to store data from the file * The functions here are used during reads to store data from the file
* into the info struct, and during writes to store application data * into the info struct, and during writes to store application data
@ -213,18 +213,18 @@ png_set_sBIT(png_structp png_ptr, png_infop info_ptr,
#if defined(PNG_READ_sRGB_SUPPORTED) || defined(PNG_WRITE_sRGB_SUPPORTED) #if defined(PNG_READ_sRGB_SUPPORTED) || defined(PNG_WRITE_sRGB_SUPPORTED)
void void
png_set_sRGB(png_structp png_ptr, png_infop info_ptr, png_byte intent) png_set_sRGB(png_structp png_ptr, png_infop info_ptr, int intent)
{ {
png_debug1(1, "in %s storage function\n", "sRGB"); png_debug1(1, "in %s storage function\n", "sRGB");
if (info_ptr == NULL) if (info_ptr == NULL)
return; return;
info_ptr->srgb_intent = intent; info_ptr->srgb_intent = (png_byte)intent;
info_ptr->valid |= PNG_INFO_sRGB; info_ptr->valid |= PNG_INFO_sRGB;
} }
void void
png_set_sRGB_gAMA_and_cHRM(png_structp png_ptr, png_infop info_ptr, png_set_sRGB_gAMA_and_cHRM(png_structp png_ptr, png_infop info_ptr,
png_byte intent) int intent)
{ {
#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_WRITE_gAMA_SUPPORTED) #if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_WRITE_gAMA_SUPPORTED)
float file_gamma; float file_gamma;
@ -239,7 +239,7 @@ png_set_sRGB_gAMA_and_cHRM(png_structp png_ptr, png_infop info_ptr,
png_set_sRGB(png_ptr, info_ptr, intent); png_set_sRGB(png_ptr, info_ptr, intent);
#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_WRITE_gAMA_SUPPORTED) #if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_WRITE_gAMA_SUPPORTED)
file_gamma = (float).45; file_gamma = (float).51;
png_set_gAMA(png_ptr, info_ptr, file_gamma); png_set_gAMA(png_ptr, info_ptr, file_gamma);
#endif #endif
@ -269,7 +269,7 @@ png_set_text(png_structp png_ptr, png_infop info_ptr, png_textp text_ptr,
int i; int i;
png_debug1(1, "in %s storage function\n", (png_ptr->chunk_name[0] == '\0' ? png_debug1(1, "in %s storage function\n", (png_ptr->chunk_name[0] == '\0' ?
"text" : png_ptr->chunk_name)); "text" : (png_const_charp)png_ptr->chunk_name));
if (info_ptr == NULL || num_text == 0) if (info_ptr == NULL || num_text == 0)
return; return;
@ -308,7 +308,7 @@ png_set_text(png_structp png_ptr, png_infop info_ptr, png_textp text_ptr,
png_textp textp = &(info_ptr->text[info_ptr->num_text]); png_textp textp = &(info_ptr->text[info_ptr->num_text]);
if (text_ptr[i].text == NULL) if (text_ptr[i].text == NULL)
text_ptr[i].text = ""; text_ptr[i].text = (png_charp)"";
if (text_ptr[i].text[0] == '\0') if (text_ptr[i].text[0] == '\0')
{ {

68
pngtest.c
View File

@ -1,12 +1,12 @@
/* pngtest.c - a simple test program to test libpng /* pngtest.c - a simple test program to test libpng
* *
* libpng 0.97 * libpng 0.98
* For conditions of distribution and use, see copyright notice in png.h * For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
* Copyright (c) 1996, 1997 Andreas Dilger * Copyright (c) 1996, 1997 Andreas Dilger
* Copyright (c) 1998, Glenn Randers-Pehrson * Copyright (c) 1998, Glenn Randers-Pehrson
* January 7, 1998 * January 16, 1998
* *
* This program reads in a PNG image, writes it out again, and then * This program reads in a PNG image, writes it out again, and then
* compares the two files. If the files are identical, this shows that * compares the two files. If the files are identical, this shows that
@ -37,6 +37,8 @@
#include "png.h" #include "png.h"
int test_one_file(PNG_CONST char *inname, PNG_CONST char *outname);
#ifdef __TURBOC__ #ifdef __TURBOC__
#include <mem.h> #include <mem.h>
#endif #endif
@ -45,10 +47,10 @@
/* #define STDERR stderr */ /* #define STDERR stderr */
#define STDERR stdout /* for DOS */ #define STDERR stdout /* for DOS */
#if defined(PNG_NO_STDIO)
/* START of code to validate stdio-free compilation */ /* START of code to validate stdio-free compilation */
/* These copies of the default read/write functions come from pngrio.c and */ /* These copies of the default read/write functions come from pngrio.c and */
/* pngwio.c. They allow "don't include stdio" testing of the library. */ /* pngwio.c. They allow "don't include stdio" testing of the library. */
#if defined(PNG_NO_STDIO)
/* This is the function which does the actual reading of data. If you are /* This is the function which does the actual reading of data. If you are
not reading from a standard C stream, you should create a replacement not reading from a standard C stream, you should create a replacement
read_data function and use it at run time with png_set_read_fn(), rather read_data function and use it at run time with png_set_read_fn(), rather
@ -118,7 +120,7 @@ png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
png_error(png_ptr, "read Error"); png_error(png_ptr, "read Error");
} }
} }
#endif #endif /* USE_FAR_KEYWORD */
#if defined(PNG_WRITE_FLUSH_SUPPORTED) #if defined(PNG_WRITE_FLUSH_SUPPORTED)
static void static void
@ -196,7 +198,7 @@ png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
} }
} }
#endif #endif /* USE_FAR_KEYWORD */
/* This function is called when there is a warning, but the library thinks /* This function is called when there is a warning, but the library thinks
* it can continue anyway. Replacement functions don't have to do anything * it can continue anyway. Replacement functions don't have to do anything
@ -224,13 +226,13 @@ png_default_error(png_structp png_ptr, png_const_charp message)
/* We can return because png_error calls the default handler which is /* We can return because png_error calls the default handler which is
* actually ok in this case. */ * actually ok in this case. */
} }
#endif #endif /* PNG_NO_STDIO */
/* END of code to validate stdio-free compilation */ /* END of code to validate stdio-free compilation */
/* Test one file */ /* Test one file */
int test(PNG_CONST char *inname, PNG_CONST char *outname) int test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
{ {
FILE *fpin, *fpout; static FILE *fpin, *fpout; /* "static" prevents setjmp corruption */
png_structp read_ptr, write_ptr; png_structp read_ptr, write_ptr;
png_infop read_info_ptr, write_info_ptr, end_info_ptr; png_infop read_info_ptr, write_info_ptr, end_info_ptr;
png_bytep row_buf; png_bytep row_buf;
@ -263,16 +265,18 @@ int test(PNG_CONST char *inname, PNG_CONST char *outname)
read_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, (png_voidp)NULL, read_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, (png_voidp)NULL,
(png_error_ptr)NULL, (png_error_ptr)NULL); (png_error_ptr)NULL, (png_error_ptr)NULL);
#if defined(PNG_NO_STDIO) #if defined(PNG_NO_STDIO)
png_set_error_fn(read_ptr, (png_voidp)inname, png_default_error, png_default_warning); png_set_error_fn(read_ptr, (png_voidp)inname, png_default_error,
png_default_warning);
#endif #endif
write_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, (png_voidp)NULL, write_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, (png_voidp)NULL,
(png_error_ptr)NULL, (png_error_ptr)NULL); (png_error_ptr)NULL, (png_error_ptr)NULL);
#if defined(PNG_NO_STDIO) #if defined(PNG_NO_STDIO)
png_set_error_fn(write_ptr, (png_voidp)inname, png_default_error, png_default_warning); png_set_error_fn(write_ptr, (png_voidp)inname, png_default_error,
png_default_warning);
#endif #endif
png_debug(0, "Allocating read_info, write_info and end_info structures\n"); png_debug(0, "Allocating read_info, write_info and end_info structures\n");
read_info_ptr = png_create_info_struct(read_ptr); read_info_ptr = png_create_info_struct(read_ptr);
write_info_ptr = png_create_info_struct(read_ptr); write_info_ptr = png_create_info_struct(write_ptr);
end_info_ptr = png_create_info_struct(read_ptr); end_info_ptr = png_create_info_struct(read_ptr);
png_debug(0, "Setting jmpbuf for read struct\n"); png_debug(0, "Setting jmpbuf for read struct\n");
@ -371,7 +375,7 @@ int test(PNG_CONST char *inname, PNG_CONST char *outname)
#endif #endif
#if defined(PNG_READ_sRGB_SUPPORTED) && defined(PNG_WRITE_sRGB_SUPPORTED) #if defined(PNG_READ_sRGB_SUPPORTED) && defined(PNG_WRITE_sRGB_SUPPORTED)
{ {
png_byte intent; int intent;
if (png_get_sRGB(read_ptr, read_info_ptr, &intent)) if (png_get_sRGB(read_ptr, read_info_ptr, &intent))
{ {
@ -515,14 +519,13 @@ int test(PNG_CONST char *inname, PNG_CONST char *outname)
png_write_end(write_ptr, end_info_ptr); png_write_end(write_ptr, end_info_ptr);
png_debug(0, "Destroying data structs\n"); png_debug(0, "Destroying data structs\n");
png_free(read_ptr, row_buf);
png_destroy_read_struct(&read_ptr, &read_info_ptr, &end_info_ptr); png_destroy_read_struct(&read_ptr, &read_info_ptr, &end_info_ptr);
png_destroy_write_struct(&write_ptr, &write_info_ptr); png_destroy_write_struct(&write_ptr, &write_info_ptr);
fclose(fpin); fclose(fpin);
fclose(fpout); fclose(fpout);
png_free(read_ptr, row_buf);
png_debug(0, "Opening files for comparison\n"); png_debug(0, "Opening files for comparison\n");
if ((fpin = fopen(inname, "rb")) == NULL) if ((fpin = fopen(inname, "rb")) == NULL)
{ {
@ -576,8 +579,8 @@ int test(PNG_CONST char *inname, PNG_CONST char *outname)
PNG_CONST char *inname = "pngtest_png"; PNG_CONST char *inname = "pngtest_png";
PNG_CONST char *outname = "pngout_png"; PNG_CONST char *outname = "pngout_png";
#else #else
PNG_CONST char *inname = "pngtest.png"; static char *inname = "pngtest.png";
PNG_CONST char *outname = "pngout.png"; static char *outname = "pngout.png";
#endif #endif
int int
@ -608,12 +611,15 @@ main(int argc, char *argv[])
if (!multiple && argc == 3) if (!multiple && argc == 3)
outname = argv[2]; outname = argv[2];
if (!multiple && argc > 3 || multiple && argc < 2) if ((!multiple && argc > 3) || (multiple && argc < 2))
{ {
fprintf(STDERR, "usage: %s [infile.png] [outfile.png]\n\t%s -m {infile.png}\n", fprintf(STDERR,
"usage: %s [infile.png] [outfile.png]\n\t%s -m {infile.png}\n",
argv[0], argv[0]); argv[0], argv[0]);
fprintf(STDERR, " reads/writes one PNG file (without -m) or multiple files (-m)\n"); fprintf(STDERR,
fprintf(STDERR, " with -m %s is used as a temporary file\n", outname); " reads/writes one PNG file (without -m) or multiple files (-m)\n");
fprintf(STDERR,
" with -m %s is used as a temporary file\n", outname);
exit(1); exit(1);
} }
@ -622,13 +628,29 @@ main(int argc, char *argv[])
int i; int i;
for (i=2; i<argc; ++i) for (i=2; i<argc; ++i)
{ {
fprintf(STDERR, "Testing %s:\n",argv[i]); int kerror;
ierror += test(argv[i], outname); fprintf(STDERR, "Testing %s:",argv[i]);
kerror = test_one_file(argv[i], outname);
if (kerror == 0) fprintf(STDERR, " PASS\n");
else {
fprintf(STDERR, " FAIL\n");
ierror += kerror;
}
} }
} }
else else
{ {
ierror += test(inname, outname); int i;
for (i=0; i<3; ++i) {
int kerror;
fprintf(STDERR, "Testing %s:",inname);
kerror = test_one_file(inname, outname);
if (kerror == 0) fprintf(STDERR, " PASS\n");
else {
fprintf(STDERR, " FAIL\n");
ierror += kerror;
}
}
} }
if (ierror == 0) if (ierror == 0)

14
pngtrans.c
View File

@ -1,12 +1,12 @@
/* pngtrans.c - transforms the data in a row (used by both readers and writers) /* pngtrans.c - transforms the data in a row (used by both readers and writers)
* *
* libpng 0.97 * libpng 0.98
* For conditions of distribution and use, see copyright notice in png.h * For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
* Copyright (c) 1996, 1997 Andreas Dilger * Copyright (c) 1996, 1997 Andreas Dilger
* Copyright (c) 1998, Glenn Randers-Pehrson * Copyright (c) 1998, Glenn Randers-Pehrson
* January 7, 1998 * January 16, 1998
*/ */
#define PNG_INTERNAL #define PNG_INTERNAL
@ -118,6 +118,16 @@ png_set_swap_alpha(png_structp png_ptr)
} }
#endif #endif
#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \
defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
void
png_set_invert_alpha(png_structp png_ptr)
{
png_debug(1, "in png_set_invert_alpha\n");
png_ptr->transformations |= PNG_INVERT_ALPHA;
}
#endif
#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) #if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED)
void void
png_set_invert_mono(png_structp png_ptr) png_set_invert_mono(png_structp png_ptr)

4
pngwio.c
View File

@ -1,12 +1,12 @@
/* pngwio.c - functions for data output /* pngwio.c - functions for data output
* *
* libpng 0.97 * libpng 0.98
* For conditions of distribution and use, see copyright notice in png.h * For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
* Copyright (c) 1996, 1997 Andreas Dilger * Copyright (c) 1996, 1997 Andreas Dilger
* Copyright (c) 1998, Glenn Randers-Pehrson * Copyright (c) 1998, Glenn Randers-Pehrson
* January 7, 1998 * January 16, 1998
* *
* This file provides a location for all output. Users which need * This file provides a location for all output. Users which need
* special handling are expected to write functions which have the same * special handling are expected to write functions which have the same

44
pngwrite.c
View File

@ -1,12 +1,12 @@
/* pngwrite.c - general routines to write a PNG file /* pngwrite.c - general routines to write a PNG file
* *
* libpng 0.97 * libpng 0.98
* For conditions of distribution and use, see copyright notice in png.h * For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
* Copyright (c) 1996, 1997 Andreas Dilger * Copyright (c) 1996, 1997 Andreas Dilger
* Copyright (c) 1998, Glenn Randers-Pehrson * Copyright (c) 1998, Glenn Randers-Pehrson
* January 7, 1998 * January 16, 1998
*/ */
/* get internal access to png.h */ /* get internal access to png.h */
@ -43,7 +43,7 @@ png_write_info(png_structp png_ptr, png_infop info_ptr)
#endif #endif
#if defined(PNG_WRITE_sRGB_SUPPORTED) #if defined(PNG_WRITE_sRGB_SUPPORTED)
if (info_ptr->valid & PNG_INFO_sRGB) if (info_ptr->valid & PNG_INFO_sRGB)
png_write_sRGB(png_ptr, info_ptr->srgb_intent); png_write_sRGB(png_ptr, (int)info_ptr->srgb_intent);
#endif #endif
#if defined(PNG_WRITE_sBIT_SUPPORTED) #if defined(PNG_WRITE_sBIT_SUPPORTED)
if (info_ptr->valid & PNG_INFO_sBIT) if (info_ptr->valid & PNG_INFO_sBIT)
@ -62,10 +62,23 @@ png_write_info(png_structp png_ptr, png_infop info_ptr)
(png_uint_32)info_ptr->num_palette); (png_uint_32)info_ptr->num_palette);
else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
png_error(png_ptr, "Valid palette required for paletted images\n"); png_error(png_ptr, "Valid palette required for paletted images\n");
#if defined(PNG_WRITE_tRNS_SUPPORTED) #if defined(PNG_WRITE_tRNS_SUPPORTED)
if (info_ptr->valid & PNG_INFO_tRNS) if (info_ptr->valid & PNG_INFO_tRNS)
{
#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
/* invert the alpha channel (in tRNS) */
if (png_ptr->transformations & PNG_INVERT_ALPHA &&
info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
{
int i;
for (i=0; i<info_ptr->num_trans; i++)
info_ptr->trans[i] = 255 - info_ptr->trans[i];
}
#endif
png_write_tRNS(png_ptr, info_ptr->trans, &(info_ptr->trans_values), png_write_tRNS(png_ptr, info_ptr->trans, &(info_ptr->trans_values),
info_ptr->num_trans, info_ptr->color_type); info_ptr->num_trans, info_ptr->color_type);
}
#endif #endif
#if defined(PNG_WRITE_bKGD_SUPPORTED) #if defined(PNG_WRITE_bKGD_SUPPORTED)
if (info_ptr->valid & PNG_INFO_bKGD) if (info_ptr->valid & PNG_INFO_bKGD)
@ -200,12 +213,12 @@ png_write_end(png_structp png_ptr, png_infop info_ptr)
png_write_IEND(png_ptr); png_write_IEND(png_ptr);
} }
#if defined(PNG_TIME_RFC1152_SUPPORTED) #if defined(PNG_TIME_RFC1123_SUPPORTED)
/* Convert the supplied time into an RFC 1152 string suitable for use in /* Convert the supplied time into an RFC 1123 string suitable for use in
* a "Creation Time" or other text-based time string. * a "Creation Time" or other text-based time string.
*/ */
png_charp png_charp
png_convert_to_rfc1152(png_structp png_ptr, png_timep ptime) png_convert_to_rfc1123(png_structp png_ptr, png_timep ptime)
{ {
const char *short_months[12] = {"Jan", "Feb", "Mar", "Apr", "May", "Jun", const char *short_months[12] = {"Jan", "Feb", "Mar", "Apr", "May", "Jun",
"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"}; "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
@ -233,7 +246,7 @@ png_convert_to_rfc1152(png_structp png_ptr, png_timep ptime)
#endif #endif
return png_ptr->time_buffer; return png_ptr->time_buffer;
} }
#endif /* PNG_TIME_RFC1152_SUPPORTED */ #endif /* PNG_TIME_RFC1123_SUPPORTED */
#if defined(PNG_WRITE_tIME_SUPPORTED) #if defined(PNG_WRITE_tIME_SUPPORTED)
void void
@ -582,6 +595,19 @@ png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
{ {
#ifdef PNG_WRITE_tEXt_SUPPORTED #ifdef PNG_WRITE_tEXt_SUPPORTED
png_free(png_ptr, info_ptr->text); png_free(png_ptr, info_ptr->text);
#endif
#if defined(PNG_READ_pCAL_SUPPORTED)
png_free(png_ptr, info_ptr->pcal_purpose);
png_free(png_ptr, info_ptr->pcal_units);
if (info_ptr->pcal_params != NULL)
{
int i;
for (i = 0; i < info_ptr->pcal_nparams; i++)
{
png_free(png_ptr, info_ptr->pcal_params[i]);
}
png_free(png_ptr, info_ptr->pcal_params);
}
#endif #endif
png_destroy_struct((png_voidp)info_ptr); png_destroy_struct((png_voidp)info_ptr);
*info_ptr_ptr = (png_infop)NULL; *info_ptr_ptr = (png_infop)NULL;
@ -617,9 +643,9 @@ png_write_destroy(png_structp png_ptr)
png_free(png_ptr, png_ptr->up_row); png_free(png_ptr, png_ptr->up_row);
png_free(png_ptr, png_ptr->avg_row); png_free(png_ptr, png_ptr->avg_row);
png_free(png_ptr, png_ptr->paeth_row); png_free(png_ptr, png_ptr->paeth_row);
#if defined(PNG_TIME_RFC1152_SUPPORTED) #if defined(PNG_TIME_RFC1123_SUPPORTED)
png_free(png_ptr, png_ptr->time_buffer); png_free(png_ptr, png_ptr->time_buffer);
#endif /* PNG_TIME_RFC1152_SUPPORTED */ #endif /* PNG_TIME_RFC1123_SUPPORTED */
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) #if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
png_free(png_ptr, png_ptr->prev_filters); png_free(png_ptr, png_ptr->prev_filters);
png_free(png_ptr, png_ptr->filter_weights); png_free(png_ptr, png_ptr->filter_weights);

84
pngwtran.c
View File

@ -1,12 +1,12 @@
/* pngwtran.c - transforms the data in a row for PNG writers /* pngwtran.c - transforms the data in a row for PNG writers
* *
* libpng 0.97 * libpng 0.98
* For conditions of distribution and use, see copyright notice in png.h * For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
* Copyright (c) 1996, 1997 Andreas Dilger * Copyright (c) 1996, 1997 Andreas Dilger
* Copyright (c) 1998, Glenn Randers-Pehrson * Copyright (c) 1998, Glenn Randers-Pehrson
* January 7, 1998 * January 16, 1998
*/ */
#define PNG_INTERNAL #define PNG_INTERNAL
@ -42,6 +42,10 @@ png_do_write_transformations(png_structp png_ptr)
if (png_ptr->transformations & PNG_SWAP_ALPHA) if (png_ptr->transformations & PNG_SWAP_ALPHA)
png_do_write_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); png_do_write_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);
#endif #endif
#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
if (png_ptr->transformations & PNG_INVERT_ALPHA)
png_do_write_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);
#endif
#if defined(PNG_WRITE_BGR_SUPPORTED) #if defined(PNG_WRITE_BGR_SUPPORTED)
if (png_ptr->transformations & PNG_BGR) if (png_ptr->transformations & PNG_BGR)
png_do_bgr(&(png_ptr->row_info), png_ptr->row_buf + 1); png_do_bgr(&(png_ptr->row_info), png_ptr->row_buf + 1);
@ -394,3 +398,79 @@ png_do_write_swap_alpha(png_row_infop row_info, png_bytep row)
} }
#endif #endif
#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
void
png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
{
png_debug(1, "in png_do_write_invert_alpha\n");
#if defined(PNG_USELESS_TESTS_SUPPORTED)
if (row != NULL && row_info != NULL)
#endif
{
if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
{
/* This inverts the alpha channel in RGBA */
if (row_info->bit_depth == 8)
{
png_bytep sp, dp;
png_uint_32 i;
for (i = 0, sp = dp = row; i < row_info->width; i++)
{
*(dp++) = *(sp++);
*(dp++) = *(sp++);
*(dp++) = *(sp++);
*(dp++) = 255 - *(sp++);
}
}
/* This inverts the alpha channel in RRGGBBAA */
else
{
png_bytep sp, dp;
png_uint_32 i;
for (i = 0, sp = dp = row; i < row_info->width; i++)
{
*(dp++) = *(sp++);
*(dp++) = *(sp++);
*(dp++) = *(sp++);
*(dp++) = *(sp++);
*(dp++) = *(sp++);
*(dp++) = *(sp++);
*(dp++) = 255 - *(sp++);
*(dp++) = 255 - *(sp++);
}
}
}
else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
{
/* This inverts the alpha channel in GA */
if (row_info->bit_depth == 8)
{
png_bytep sp, dp;
png_uint_32 i;
for (i = 0, sp = dp = row; i < row_info->width; i++)
{
*(dp++) = *(sp++);
*(dp++) = 255 - *(sp++);
}
}
/* This inverts the alpha channel in GGAA */
else
{
png_bytep sp, dp;
png_uint_32 i;
for (i = 0, sp = dp = row; i < row_info->width; i++)
{
*(dp++) = *(sp++);
*(dp++) = *(sp++);
*(dp++) = 255 - *(sp++);
*(dp++) = 255 - *(sp++);
}
}
}
}
}
#endif

13
pngwutil.c
View File

@ -1,12 +1,12 @@
/* pngwutil.c - utilities to write a PNG file /* pngwutil.c - utilities to write a PNG file
* *
* libpng 0.97 * libpng 0.98
* For conditions of distribution and use, see copyright notice in png.h * For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
* Copyright (c) 1996, 1997 Andreas Dilger * Copyright (c) 1996, 1997 Andreas Dilger
* Copyright (c) 1998, Glenn Randers-Pehrson * Copyright (c) 1998, Glenn Randers-Pehrson
* January 7, 1998 * January 16, 1998
*/ */
#define PNG_INTERNAL #define PNG_INTERNAL
@ -346,7 +346,7 @@ png_write_gAMA(png_structp png_ptr, double file_gamma)
#if defined(PNG_WRITE_sRGB_SUPPORTED) #if defined(PNG_WRITE_sRGB_SUPPORTED)
/* write a sRGB chunk */ /* write a sRGB chunk */
void void
png_write_sRGB(png_structp png_ptr, png_byte srgb_intent) png_write_sRGB(png_structp png_ptr, int srgb_intent)
{ {
png_byte buf[1]; png_byte buf[1];
@ -354,7 +354,7 @@ png_write_sRGB(png_structp png_ptr, png_byte srgb_intent)
if(srgb_intent > 3) if(srgb_intent > 3)
png_warning(png_ptr, png_warning(png_ptr,
"Invalid sRGB rendering intent specified"); "Invalid sRGB rendering intent specified");
buf[0]=srgb_intent; buf[0]=(png_byte)srgb_intent;
png_write_chunk(png_ptr, png_sRGB, buf, (png_size_t)1); png_write_chunk(png_ptr, png_sRGB, buf, (png_size_t)1);
} }
#endif #endif
@ -506,7 +506,7 @@ png_write_tRNS(png_structp png_ptr, png_bytep trans, png_color_16p tran,
} }
else else
{ {
png_warning(png_ptr, "Can't write tRNS with and alpha channel"); png_warning(png_ptr, "Can't write tRNS with an alpha channel");
} }
} }
#endif #endif
@ -992,6 +992,7 @@ png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0,
(png_size_t)params_len[i]); (png_size_t)params_len[i]);
} }
png_free(png_ptr, params_len);
png_write_chunk_end(png_ptr); png_write_chunk_end(png_ptr);
} }
#endif #endif
@ -1395,7 +1396,7 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
* smallest value when summing the absolute values of the distances * smallest value when summing the absolute values of the distances
* from zero using anything >= 128 as negative numbers. This is known * from zero using anything >= 128 as negative numbers. This is known
* as the "minimum sum of absolute differences" heuristic. Other * as the "minimum sum of absolute differences" heuristic. Other
* heruistics are the "weighted minumum sum of absolute differences" * heuristics are the "weighted minumum sum of absolute differences"
* (experimental and can in theory improve compression), and the "zlib * (experimental and can in theory improve compression), and the "zlib
* predictive" method (not implemented in libpng 0.95), which does test * predictive" method (not implemented in libpng 0.95), which does test
* compressions of lines using different filter methods, and then chooses * compressions of lines using different filter methods, and then chooses