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Imported from libpng-1.0.10beta1.tar

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This commit is contained in:
Glenn Randers-Pehrson 2001-03-14 07:08:39 -06:00
parent d4e8109a48
commit 1909560348
52 changed files with 1171 additions and 694 deletions
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63
ANNOUNCE
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@ -1,58 +1,21 @@
Libpng 1.0.9 - January 31, 2001
Libpng 1.0.10beta1 - March 14, 2001
This is a public release of libpng, intended for use in production codes.
Changes since the last public release (1.0.8):
Changes since the last public release (1.0.9):
Fixed typo in scripts/makefile.hpux
Fixed seqence-point bug in contrib/pngminus/png2pnm (Martin Zinser)
Updated makevms.com in scripts and contrib/* and contrib/* (Martin Zinser)
Changed "cdrom.com" in documentation to "libpng.org"
Revised pnggccrd.c to get it all working, and updated makefile.gcmmx (Greg).
Changed type of "params" from voidp to png_voidp in png_read|write_png().
Added MNG_EXTENSIONS_SUPPORTED macro and support for some proposed MNG
features, for testing purposes.
Make sure PNGAPI and PNG_IMPEXP are defined in pngconf.h.
Revised the 3 instances of WRITEFILE in pngtest.c.
Updated png.rc in dll/msvc project
Revised makefile.dec to define and use LIBPATH and INCPATH
Increased size of global png_libpng_ver[] array from 12 to 18 chars.
Made global png_libpng_ver[], png_sig[] and png_pass_*[] arrays const.
Removed duplicate png_crc_finish() from png_handle_bKGD() function.
Added a warning when application calls png_read_update_info() multiple times.
Revised makefile.cygwin
Fixed bugs in iCCP support in pngrutil.c and pngwutil.c.
Replaced png_set_empty_plte_permitted() with png_permit_mng_features().
Relocated "msvc" and "wince" project subdirectories into "projects"
subdirectory and added projects/borland project subdirectory.
Set VS_FF_PRERELEASE and VS_FF_PATCHED flags in msvc/png.rc when appropriate.
Add error message in png_set_compression_buffer_size() when malloc fails.
Revised PNG_LIBPNG_BUILD_TYPE macro in png.h, used in the msvc project.
Removed the png_flush() in pngwrite.c that crashes some applications
that don't set png_output_flush_fn.
Added makefile.macosx and makefile.aix to scripts directory.
Change png_chunk_warning to png_warning in png_check_keyword().
Increased the first part of msg buffer from 16 to 18 in png_chunk_error().
Added support for filter method 64 (for PNG datastreams embedded in MNG)
Revised png_set_filter() to accept filter method 64 when appropriate.
Added new PNG_HAVE_PNG_SIGNATURE bit to png_ptr->mode and use it to
help prevent applications from using MNG features in PNG datastreams.
Revised libpng.3/libpng.txt. Changed "filter type" to "filter method".
Fixed error handling of unknown compression type in png_decompress_chunk().
In pngconf.h, define __cdecl when _MSC_VER is defined.
Changed PNG_TEXT_COMPRESSION_zTXt to PNG_COMPRESSION_TYPE_BASE several places.
Revised memory management in png_set_hIST and png_handle_hIST in a backward
compatible manner. PLTE and tRNS were revised similarly.
Revised the iCCP chunk reader to ignore trailing garbage.
Moved pngasmrd.h into pngconf.h.
Improved handling of out-of-spec garbage iCCP chunks generated by PhotoShop.
Added png_set_invalid to wince and msvc project module definition files.
Fixed bug with progressive reading of narrow interlaced images in pngpread.c
Do not typedef png_FILE_io in pngconf.h when PNG_NO_STDIO is defined.
Updated makefile.sgi to make shared library.
Added check of cygwin's ALL_STATIC in pngconf.h
Added "-nommx" parameter to contrib/gregbook/rpng2-win and rpng2-x demos.
Revised makefile.dec
Reformatted libpng.3 to eliminate bad line breaks.
Added checks for _mmx_supported in the read_filter_row function of pnggccrd.c
Added prototype for png_mmx_support() near the top of pnggccrd.c
Moved some error checking from png_handle_IHDR to png_set_IHDR.
Added PNG_NO_READ_SUPPORTED and PNG_NO_WRITE_SUPPORTED macros.
Revised png_mmx_support() function in pnggccrd.c
Restored version 1.0.8 PNG_WRITE_EMPTY_PLTE_SUPPORTED behavior in pngwutil.c
Fixed memory leak in contrib/visupng/PngFile.c
Fixed bugs in png_combine_row() in pnggccrd.c and pngvcrd.c (C version)
Added warnings when retrieving or setting gamma=0.
Send comments/corrections/commendations to
png-implement@ccrc.wustl.edu or to randeg@alum.rpi.edu

13
CHANGES
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@ -893,6 +893,19 @@ version 1.0.9rc2 [January 22, 2001]
version 1.0.9 [January 31, 2001]
Added check of cygwin's ALL_STATIC in pngconf.h
Added "-nommx" parameter to contrib/gregbook/rpng2-win and rpng2-x demos.
version 1.0.10beta1 [March 14, 2001]
Revised makefile.dec, makefile.sgi, and makefile.sggcc; added makefile.hpgcc.
Reformatted libpng.3 to eliminate bad line breaks.
Added checks for _mmx_supported in the read_filter_row function of pnggccrd.c
Added prototype for png_mmx_support() near the top of pnggccrd.c
Moved some error checking from png_handle_IHDR to png_set_IHDR.
Added PNG_NO_READ_SUPPORTED and PNG_NO_WRITE_SUPPORTED macros.
Revised png_mmx_support() function in pnggccrd.c
Restored version 1.0.8 PNG_WRITE_EMPTY_PLTE_SUPPORTED behavior in pngwutil.c
Fixed memory leak in contrib/visupng/PngFile.c
Fixed bugs in png_combine_row() in pnggccrd.c and pngvcrd.c (C version)
Added warnings when retrieving or setting gamma=0.
Increased the first part of msg buffer from 16 to 18 in png_chunk_warning().
Send comments/corrections/commendations to
png-implement@ccrc.wustl.edu or to randeg@alum.rpi.edu

13
INSTALL
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@ -1,5 +1,5 @@
Installing libpng version 1.0.9 - January 31, 2001
Installing libpng version 1.0.10beta1 - March 14, 2001
Before installing libpng, you must first install zlib. zlib
can usually be found wherever you got libpng. zlib can be
@ -10,7 +10,7 @@ zlib.h and zconf.h include files that correspond to the
version of zlib that's installed.
You can rename the directories that you downloaded (they
might be called "libpng-1.0.9" or "lpng109" and "zlib-1.1.3"
might be called "libpng-1.0.10beta1" or "lpng109" and "zlib-1.1.3"
or "zlib113") so that you have directories called "zlib" and "libpng".
Your directory structure should look like this:
@ -59,8 +59,8 @@ The files that are presently available in the scripts directory
include
makefile.std => Generic UNIX makefile (cc, creates static libpng.a)
makefile.linux => Linux/ELF makefile (gcc, creates libpng.so.2.1.0.9)
makefile.gcmmx => Linux/ELF makefile (gcc, creates libpng.so.2.1.0.9,
makefile.linux => Linux/ELF makefile (gcc, creates libpng.so.2.1.0.10beta1)
makefile.gcmmx => Linux/ELF makefile (gcc, creates libpng.so.2.1.0.10beta1,
uses assembler code tuned for Intel MMX platform)
makefile.gcc => Generic makefile (gcc, creates static libpng.a)
makefile.knr => Archaic UNIX Makefile that converts files with
@ -69,15 +69,16 @@ include
makefile.aix => AIX makefile
makefile.cygwin => Cygwin/gcc makefile
makefile.dec => DEC Alpha UNIX makefile
makefile.hpgcc => HPUX makefile using gcc
makefile.hpux => HPUX (10.20 and 11.00) makefile
makefile.ibmc => IBM C/C++ version 3.x for Win32 and OS/2 (static)
makefile.intel => Intel C/C++ version 4.0 and later
libpng.icc => Project file for IBM VisualAge/C++ version 4.0 or later
makefile.macosx => MACOS X Makefile
makefile.sgi => Silicon Graphics IRIX makefile (cc, creates static lib)
makefile.sggcc => Silicon Graphics (gcc, creates libpng.so.2.1.0.9)
makefile.sggcc => Silicon Graphics (gcc, creates libpng.so.2.1.0.10beta1)
makefile.sunos => Sun makefile
makefile.solaris => Solaris 2.X makefile (gcc, creates libpng.so.2.1.0.9)
makefile.solaris => Solaris 2.X makefile (gcc, creates libpng.so.2.1.0.10beta1)
makefile.sco => For SCO OSr5 ELF and Unixware 7 with Native cc
makefile.mips => MIPS makefile
makefile.acorn => Acorn makefile

4
KNOWNBUG
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@ -1,4 +1,4 @@
Known bugs in libpng-1.0.9
Known bugs in libpng-1.0.10
None.
None as of March 14, 2001.

14
LICENSE
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@ -8,8 +8,8 @@ COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
If you modify libpng you may insert additional notices immediately following
this sentence.
libpng versions 1.0.7, July 1, 2000, through 1.0.9, January 31, 2001, are
Copyright (c) 2000 Glenn Randers-Pehrson
libpng versions 1.0.7, July 1, 2000, through 1.0.10beta1, March 14, 2001, are
Copyright (c) 2000, 2001 Glenn Randers-Pehrson
and are distributed according to the same disclaimer and license as libpng-1.0.6
with the following individuals added to the list of Contributing Authors
@ -73,11 +73,11 @@ to the following restrictions:
1. The origin of this source code must not be misrepresented.
2. Altered versions must be plainly marked as such and must not
be misrepresented as being the original source.
2. Altered versions must be plainly marked as such and
must not be misrepresented as being the original source.
3. This Copyright notice may not be removed or altered from any
source or altered source distribution.
3. This Copyright notice may not be removed or altered from
any source or altered source distribution.
The Contributing Authors and Group 42, Inc. specifically permit, without
fee, and encourage the use of this source code as a component to
@ -99,4 +99,4 @@ certification mark of the Open Source Initiative.
Glenn Randers-Pehrson
randeg@alum.rpi.edu
January 31, 2001
March 14, 2001

11
README
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@ -1,4 +1,4 @@
README for libpng 1.0.9 - January 31, 2001 (shared library 2.1)
README for libpng 1.0.10beta1 - March 14, 2001 (shared library 2.1)
See the note about version numbers near the top of png.h
See INSTALL for instructions on how to install libpng.
@ -182,9 +182,9 @@ Files in this distribution:
descrip.mms => VMS makefile for MMS or MMK
makefile.std => Generic UNIX makefile (cc, creates static libpng.a)
makefile.linux => Linux/ELF makefile
(gcc, creates libpng.so.2.1.0.9)
(gcc, creates libpng.so.2.1.0.10beta1)
makefile.gcmmx => Linux/ELF makefile (gcc, creates
libpng.so.2.1.0.9, uses assembler code
libpng.so.2.1.0.10beta1, uses assembler code
tuned for Intel MMX platform)
makefile.gcc => Generic makefile (gcc, creates static libpng.a)
makefile.knr => Archaic UNIX Makefile that converts files with
@ -193,16 +193,17 @@ Files in this distribution:
makefile.aix => AIX makefile
makefile.cygwin => Cygwin/gcc makefile
makefile.dec => DEC Alpha UNIX makefile
makefile.hpgcc => HPUX makefile using gcc
makefile.hpux => HPUX (10.20 and 11.00) makefile
makefile.ibmc => IBM C/C++ version 3.x for Win32 and OS/2 (static)
makefile.intel => Intel C/C++ version 4.0 and later
libpng.icc => Project file, IBM VisualAge/C++ 4.0 or later
makefile.macosx => MACOS X Makefile
makefile.sgi => Silicon Graphics IRIX (cc, creates static lib)
makefile.sggcc => Silicon Graphics (gcc, creates libpng.so.2.1.0.9)
makefile.sggcc => Silicon Graphics (gcc, creates libpng.so.2.1.0.10beta1)
makefile.sunos => Sun makefile
makefile.solaris => Solaris 2.X makefile
(gcc, creates libpng.so.2.1.0.9)
(gcc, creates libpng.so.2.1.0.10beta1)
makefile.sco => For SCO OSr5 ELF and Unixware 7 with Native cc
makefile.mips => MIPS makefile
makefile.acorn => Acorn makefile

4
Y2KINFO
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@ -1,13 +1,13 @@
Y2K compliance in libpng:
=========================
January 31, 2001
March 14, 2001
Since the PNG Development group is an ad-hoc body, we can't make
an official declaration.
This is your unofficial assurance that libpng from version 0.71 and
upward through 1.0.9 are Y2K compliant. It is my belief that earlier
upward through 1.0.10beta1 are Y2K compliant. It is my belief that earlier
versions were also Y2K compliant.
Libpng only has three year fields. One is a 2-byte unsigned integer

2
configure vendored
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@ -1,5 +1,5 @@
echo "
There is no \"configure\" script for Libpng-1.0.9. Instead, please
There is no \"configure\" script for Libpng-1.0.10beta1. Instead, please
copy the appropriate makefile for your system from the \"scripts\"
directory. Read the INSTALL file for more details.
"

4
contrib/visupng/PngFile.c
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@ -370,14 +370,14 @@ BOOL PngSaveImage (PTSTR pstrFileName, png_byte *pDiData,
// clean up after the write, and free any memory allocated
png_destroy_write_struct(&png_ptr, (png_infopp) NULL);
png_destroy_write_struct(&png_ptr, &info_ptr);
// yepp, done
}
Catch (msg)
{
png_destroy_write_struct(&png_ptr, (png_infopp) NULL);
png_destroy_write_struct(&png_ptr, &info_ptr);
if(ppbRowPointers)
free (ppbRowPointers);

361
libpng.3
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@ -1,6 +1,6 @@
.TH LIBPNG 3 "January 31, 2001"
.TH LIBPNG 3 "March 14, 2001"
.SH NAME
libpng \- Portable Network Graphics (PNG) Reference Library 1.0.9
libpng \- Portable Network Graphics (PNG) Reference Library 1.0.10beta1
.SH SYNOPSIS
\fI\fB
@ -747,7 +747,7 @@ Following is a copy of the libpng.txt file that accompanies libpng.
.SH LIBPNG.TXT
libpng.txt - A description on how to use and modify libpng
libpng version 1.0.9 - January 31, 2001
libpng version 1.0.10beta1 - March 14, 2001
Updated and distributed by Glenn Randers-Pehrson
<randeg@alum.rpi.edu>
Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson
@ -1004,10 +1004,11 @@ input stream. You must supply the function
png_byte name[5];
png_byte *data;
png_size_t size;
/* Note that libpng has already taken care of the
CRC handling */
/* Note that libpng has already taken care of
the CRC handling */
/* put your code here. Return one of the following: */
/* put your code here. Return one of the
following: */
return (-n); /* chunk had an error */
return (0); /* did not recognize */
@ -1078,16 +1079,23 @@ the entire image into memory, and (b) the input transformations
you want to do are limited to the following set:
PNG_TRANSFORM_IDENTITY No transformation
PNG_TRANSFORM_STRIP_16 Strip 16-bit samples to 8 bits
PNG_TRANSFORM_STRIP_16 Strip 16-bit samples to
8 bits
PNG_TRANSFORM_STRIP_ALPHA Discard the alpha channel
PNG_TRANSFORM_PACKING Expand 1, 2 and 4-bit samples to bytes
PNG_TRANSFORM_PACKSWAP Change order of packed pixels to LSB first
PNG_TRANSFORM_PACKING Expand 1, 2 and 4-bit
samples to bytes
PNG_TRANSFORM_PACKSWAP Change order of packed
pixels to LSB first
PNG_TRANSFORM_EXPAND Perform set_expand()
PNG_TRANSFORM_INVERT_MONO Invert monochrome images
PNG_TRANSFORM_SHIFT Normalize pixels to the sBIT depth
PNG_TRANSFORM_BGR Flip RGB to BGR, RGBA to BGRA
PNG_TRANSFORM_SWAP_ALPHA Flip RGBA to ARGB or GA to AG
PNG_TRANSFORM_INVERT_ALPHA Change alpha from opacity to transparency
PNG_TRANSFORM_SHIFT Normalize pixels to the
sBIT depth
PNG_TRANSFORM_BGR Flip RGB to BGR, RGBA
to BGRA
PNG_TRANSFORM_SWAP_ALPHA Flip RGBA to ARGB or GA
to AG
PNG_TRANSFORM_INVERT_ALPHA Change alpha from opacity
to transparency
PNG_TRANSFORM_SWAP_ENDIAN Byte-swap 16-bit samples
(This excludes setting a background color, doing gamma transformation,
@ -1115,9 +1123,11 @@ where row_pointers is an array of pointers to the pixel data for each row:
If you know your image size and pixel size ahead of time, you can allocate
row_pointers prior to calling png_read_png() with
row_pointers = png_malloc(png_ptr, height*sizeof(png_bytep));
row_pointers = png_malloc(png_ptr,
height*sizeof(png_bytep));
for (int i=0; i<height, i++)
row_pointers[i]=png_malloc(png_ptr, width*pixel_size);
row_pointers[i]=png_malloc(png_ptr,
width*pixel_size);
png_set_rows(png_ptr, info_ptr, &row_pointers);
Alternatively you could allocate your image in one big block and define
@ -1185,8 +1195,8 @@ in until png_read_end() has read the chunk data following the image.
interlace_type - (PNG_INTERLACE_NONE or
PNG_INTERLACE_ADAM7)
Any or all of interlace_type, compression_type, of
filter_method can be NULL if you are
not interested in their values.
filter_method can be NULL if you are
not interested in their values.
channels = png_get_channels(png_ptr, info_ptr);
channels - number of channels of info for the
@ -1249,14 +1259,15 @@ into the info_ptr is returned for any complex types.
implies specific values of gAMA and
cHRM.
png_get_iCCP(png_ptr, info_ptr, &name, &compression_type,
&profile, &proflen);
png_get_iCCP(png_ptr, info_ptr, &name,
&compression_type, &profile, &proflen);
name - The profile name.
compression - The compression type; always PNG_COMPRESSION_TYPE_BASE
for PNG 1.0. You may give NULL to this argument
to ignore it.
profile - International Color Consortium color profile
data. May contain NULs.
compression - The compression type; always
PNG_COMPRESSION_TYPE_BASE for PNG 1.0.
You may give NULL to this argument to
ignore it.
profile - International Color Consortium color
profile data. May contain NULs.
proflen - length of profile data in bytes.
png_get_sBIT(png_ptr, info_ptr, &sig_bit);
@ -1312,21 +1323,24 @@ into the info_ptr is returned for any complex types.
string for unknown).
text_ptr[i].translated_keyword - keyword in UTF-8
(empty string for unknown).
num_text - number of comments (same as num_comments;
you can put NULL here to avoid the duplication)
Note while png_set_text() will accept text, language, and
translated keywords that can be NULL pointers, the structure
returned by png_get_text will always contain regular
zero-terminated C strings. They might be empty strings but
they will never be NULL pointers.
num_text - number of comments (same as
num_comments; you can put NULL here
to avoid the duplication)
Note while png_set_text() will accept text, language,
and translated keywords that can be NULL pointers, the
structure returned by png_get_text will always contain
regular zero-terminated C strings. They might be
empty strings but they will never be NULL pointers.
num_spalettes = png_get_sPLT(png_ptr, info_ptr, &palette_ptr);
num_spalettes = png_get_sPLT(png_ptr, info_ptr,
&palette_ptr);
palette_ptr - array of palette structures holding
contents of one or more sPLT chunks read.
contents of one or more sPLT chunks
read.
num_spalettes - number of sPLT chunks read.
png_get_oFFs(png_ptr, info_ptr, &offset_x, &offset_y,
&unit_type);
&unit_type);
offset_x - positive offset from the left edge
of the screen
offset_y - positive offset from the top edge
@ -1334,7 +1348,7 @@ into the info_ptr is returned for any complex types.
unit_type - PNG_OFFSET_PIXEL, PNG_OFFSET_MICROMETER
png_get_pHYs(png_ptr, info_ptr, &res_x, &res_y,
&unit_type);
&unit_type);
res_x - pixels/unit physical resolution in
x direction
res_y - pixels/unit physical resolution in
@ -1342,47 +1356,50 @@ into the info_ptr is returned for any complex types.
unit_type - PNG_RESOLUTION_UNKNOWN,
PNG_RESOLUTION_METER
png_get_sCAL(png_ptr, info_ptr, &unit, &width, &height)
png_get_sCAL(png_ptr, info_ptr, &unit, &width,
&height)
unit - physical scale units (an integer)
width - width of a pixel in physical scale units
height - height of a pixel in physical scale units
(width and height are doubles)
png_get_sCAL_s(png_ptr, info_ptr, &unit, &width, &height)
png_get_sCAL_s(png_ptr, info_ptr, &unit, &width,
&height)
unit - physical scale units (an integer)
width - width of a pixel in physical scale units
height - height of a pixel in physical scale units
(width and height are strings like "2.54")
num_unknown_chunks = png_get_unknown_chunks(png_ptr, info_ptr,
&unknowns)
unknowns - array of png_unknown_chunk structures holding
unknown chunks
num_unknown_chunks = png_get_unknown_chunks(png_ptr,
info_ptr, &unknowns)
unknowns - array of png_unknown_chunk
structures holding unknown chunks
unknowns[i].name - name of unknown chunk
unknowns[i].data - data of unknown chunk
unknowns[i].size - size of unknown chunk's data
unknowns[i].location - position of chunk in file
The value of "i" corresponds to the order in which the chunks were read
from the PNG file or inserted with the png_set_unknown_chunks() function.
The value of "i" corresponds to the order in which the
chunks were read from the PNG file or inserted with the
png_set_unknown_chunks() function.
The data from the pHYs chunk can be retrieved in several convenient
forms:
res_x = png_get_x_pixels_per_meter(png_ptr,
info_ptr)
info_ptr)
res_y = png_get_y_pixels_per_meter(png_ptr,
info_ptr)
info_ptr)
res_x_and_y = png_get_pixels_per_meter(png_ptr,
info_ptr)
info_ptr)
res_x = png_get_x_pixels_per_inch(png_ptr,
info_ptr)
info_ptr)
res_y = png_get_y_pixels_per_inch(png_ptr,
info_ptr)
info_ptr)
res_x_and_y = png_get_pixels_per_inch(png_ptr,
info_ptr)
info_ptr)
aspect_ratio = png_get_pixel_aspect_ratio(png_ptr,
info_ptr)
info_ptr)
(Each of these returns 0 [signifying "unknown"] if
the data is not present or if res_x is 0;
@ -1397,8 +1414,8 @@ forms:
y_offset = png_get_y_offset_inches(png_ptr, info_ptr);
(Each of these returns 0 [signifying "unknown" if both
x and y are 0] if the data is not present or if the chunk
is present but the unit is the pixel)
x and y are 0] if the data is not present or if the
chunk is present but the unit is the pixel)
For more information, see the png_info definition in png.h and the
PNG specification for chunk contents. Be careful with trusting
@ -1932,7 +1949,7 @@ When you are done, you can free all memory allocated by libpng like this:
It is also possible to individually free the info_ptr members that
point to libpng-allocated storage with the following function:
png_free_data(png_ptr, info_ptr, mask, n)
png_free_data(png_ptr, info_ptr, mask, seq)
mask - identifies data to be freed, a mask
containing the logical OR of one or
more of
@ -1942,16 +1959,17 @@ point to libpng-allocated storage with the following function:
PNG_FREE_SCAL, PNG_FREE_SPLT,
PNG_FREE_TEXT, PNG_FREE_UNKN,
or simply PNG_FREE_ALL
n - sequence number of item to be freed
seq - sequence number of item to be freed
(-1 for all items)
This function may be safely called when the relevant storage has
already been freed, or has not yet been allocated, or was allocated
by the user and not by libpng, and will in those
cases do nothing. The "n" parameter is ignored if only one item
of the selected data type, such as PLTE, is allowed. If "n" is not
cases do nothing. The "seq" parameter is ignored if only one item
of the selected data type, such as PLTE, is allowed. If "seq" is not
-1, and multiple items are allowed for the data type identified in
the mask, such as text or sPLT, only the n'th item is freed.
the mask, such as text or sPLT, only the n'th item in the structure
is freed, where n is "seq".
The default behavior is only to free data that was allocated internally
by libpng. This can be changed, so that libpng will not free the data,
@ -2124,9 +2142,10 @@ png_infop info_ptr;
/* This function is called when each row of image
data is complete */
void
row_callback(png_structp png_ptr, png_bytep new_row,
png_uint_32 row_num, int pass)
png_uint_32 row_num, int pass)
{
/* If the image is interlaced, and you turned
on the interlace handler, this function will
@ -2270,7 +2289,8 @@ called after each row has been written, which you can use to control
a progress meter or the like. It's demonstrated in pngtest.c.
You must supply a function
void write_row_callback(png_ptr, png_uint_32 row, int pass);
void write_row_callback(png_ptr, png_uint_32 row,
int pass);
{
/* put your code here */
}
@ -2298,8 +2318,9 @@ types.
/* turn on or off filtering, and/or choose
specific filters. You can use either a single PNG_FILTER_VALUE_NAME
or the logical OR of one or more PNG_FILTER_NAME masks. */
specific filters. You can use either a single
PNG_FILTER_VALUE_NAME or the logical OR of one
or more PNG_FILTER_NAME masks. */
png_set_filter(png_ptr, 0,
PNG_FILTER_NONE | PNG_FILTER_VALUE_NONE |
PNG_FILTER_SUB | PNG_FILTER_VALUE_SUB |
@ -2435,11 +2456,12 @@ Some of the more important parts of the png_info are:
png_set_iCCP(png_ptr, info_ptr, name, compression_type,
profile, proflen);
name - The profile name.
compression - The compression type; always PNG_COMPRESSION_TYPE_BASE
for PNG 1.0. You may give NULL to this argument
to ignore it.
profile - International Color Consortium color profile
data. May contain NULs.
compression - The compression type; always
PNG_COMPRESSION_TYPE_BASE for PNG 1.0.
You may give NULL to this argument to
ignore it.
profile - International Color Consortium color
profile data. May contain NULs.
proflen - length of profile data in bytes.
png_set_sBIT(png_ptr, info_ptr, sig_bit);
@ -2493,11 +2515,13 @@ Some of the more important parts of the png_info are:
or empty for unknown).
num_text - number of comments
png_set_sPLT(png_ptr, info_ptr, &palette_ptr, num_spalettes);
palette_ptr - array of png_sPLT_struct structures to be
added to the list of palettes in the info
structure.
num_spalettes - number of palette structures to be added.
png_set_sPLT(png_ptr, info_ptr, &palette_ptr,
num_spalettes);
palette_ptr - array of png_sPLT_struct structures
to be added to the list of palettes
in the info structure.
num_spalettes - number of palette structures to be
added.
png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y,
unit_type);
@ -2528,9 +2552,10 @@ Some of the more important parts of the png_info are:
height - height of a pixel in physical scale units
(width and height are strings like "2.54")
png_set_unknown_chunks(png_ptr, info_ptr, &unknowns, num_unknowns)
unknowns - array of png_unknown_chunk structures holding
unknown chunks
png_set_unknown_chunks(png_ptr, info_ptr, &unknowns,
num_unknowns)
unknowns - array of png_unknown_chunk
structures holding unknown chunks
unknowns[i].name - name of unknown chunk
unknowns[i].data - data of unknown chunk
unknowns[i].size - size of unknown chunk's data
@ -2539,14 +2564,15 @@ Some of the more important parts of the png_info are:
PNG_HAVE_IHDR: before PLTE
PNG_HAVE_PLTE: before IDAT
PNG_AFTER_IDAT: after IDAT
The "location" member is set automatically according to
what part of the output file has already been written.
You can change its value after calling png_set_unknown_chunks()
as demonstrated in pngtest.c. Within each of the "locations",
the chunks are sequenced according to their position in the
structure (that is, the value of "i", which is the order in which
the chunk was either read from the input file or defined with
png_set_unknown_chunks).
The "location" member is set automatically according to
what part of the output file has already been written.
You can change its value after calling png_set_unknown_chunks()
as demonstrated in pngtest.c. Within each of the "locations",
the chunks are sequenced according to their position in the
structure (that is, the value of "i", which is the order in which
the chunk was either read from the input file or defined with
png_set_unknown_chunks).
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.
@ -2647,12 +2673,17 @@ transformations are permitted, enabled by the following masks.
PNG_TRANSFORM_IDENTITY No transformation
PNG_TRANSFORM_PACKING Pack 1, 2 and 4-bit samples
PNG_TRANSFORM_PACKSWAP Change order of packed pixels to LSB first
PNG_TRANSFORM_PACKSWAP Change order of packed
pixels to LSB first
PNG_TRANSFORM_INVERT_MONO Invert monochrome images
PNG_TRANSFORM_SHIFT Normalize pixels to the sBIT depth
PNG_TRANSFORM_BGR Flip RGB to BGR, RGBA to BGRA
PNG_TRANSFORM_SWAP_ALPHA Flip RGBA to ARGB or GA to AG
PNG_TRANSFORM_INVERT_ALPHA Change alpha from opacity to transparency
PNG_TRANSFORM_SHIFT Normalize pixels to the
sBIT depth
PNG_TRANSFORM_BGR Flip RGB to BGR, RGBA
to BGRA
PNG_TRANSFORM_SWAP_ALPHA Flip RGBA to ARGB or GA
to AG
PNG_TRANSFORM_INVERT_ALPHA Change alpha from opacity
to transparency
PNG_TRANSFORM_SWAP_ENDIAN Byte-swap 16-bit samples
PNG_TRANSFORM_STRIP_FILLER Strip out filler bytes.
@ -2916,7 +2947,7 @@ When you are done, you can free all memory used by libpng like this:
It is also possible to individually free the info_ptr members that
point to libpng-allocated storage with the following function:
png_free_data(png_ptr, info_ptr, mask, n)
png_free_data(png_ptr, info_ptr, mask, seq)
mask - identifies data to be freed, a mask
containing the logical OR of one or
more of
@ -2926,16 +2957,17 @@ point to libpng-allocated storage with the following function:
PNG_FREE_SCAL, PNG_FREE_SPLT,
PNG_FREE_TEXT, PNG_FREE_UNKN,
or simply PNG_FREE_ALL
n - sequence number of item to be freed
seq - sequence number of item to be freed
(-1 for all items)
This function may be safely called when the relevant storage has
already been freed, or has not yet been allocated, or was allocated
by the user and not by libpng, and will in those
cases do nothing. The "n" parameter is ignored if only one item
of the selected data type, such as PLTE, is allowed. If "n" is not
cases do nothing. The "seq" parameter is ignored if only one item
of the selected data type, such as PLTE, is allowed. If "seq" is not
-1, and multiple items are allowed for the data type identified in
the mask, such as text or sPLT, only the n'th item is freed.
the mask, such as text or sPLT, only the n'th item in the structure
is freed, where n is "seq".
If you allocated data such as a palette that you passed
in to libpng with png_set_*, you must not free it until just before the call to
@ -3016,8 +3048,8 @@ memory allocation on a platform will change between applications, these
functions must be modified in the library at compile time. If you prefer
to use a different method of allocating and freeing data, you can use
png_set_mem_fn(png_structp png_ptr, png_voidp mem_ptr, png_malloc_ptr
malloc_fn, png_free_ptr free_fn)
png_set_mem_fn(png_structp png_ptr, png_voidp mem_ptr,
png_malloc_ptr malloc_fn, png_free_ptr free_fn)
This function also provides a void pointer that can be retrieved via
@ -3025,7 +3057,8 @@ This function also provides a void pointer that can be retrieved via
Your replacement memory functions must have prototypes as follows:
png_voidp malloc_fn(png_structp png_ptr, png_uint_32 size);
png_voidp malloc_fn(png_structp png_ptr,
png_uint_32 size);
void free_fn(png_structp png_ptr, png_voidp ptr);
Input/Output in libpng is done through png_read() and png_write(),
@ -3237,10 +3270,12 @@ structures appropriately for all of the filter types.
png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE,
filters);
The second parameter can also be PNG_INTRAPIXEL_DIFFERENCING
if you are writing a PNG to be embedded in a MNG
datastream. This parameter must be the same as the
value of filter_method used in png_set_IHDR().
The second parameter can also be
PNG_INTRAPIXEL_DIFFERENCING if you are
writing a PNG to be embedded in a MNG
datastream. This parameter must be the
same as the value of filter_method used
in png_set_IHDR().
It is also possible to influence how libpng chooses from among the
available filters. This is done in two ways - by telling it how
@ -3429,13 +3464,13 @@ application:
.SH VIII. Y2K Compliance in libpng
January 31, 2001
March 14, 2001
Since the PNG Development group is an ad-hoc body, we can't make
an official declaration.
This is your unofficial assurance that libpng from version 0.71 and
upward through 1.0.9 are Y2K compliant. It is my belief that earlier
upward through 1.0.10beta1 are Y2K compliant. It is my belief that earlier
versions were also Y2K compliant.
Libpng only has three year fields. One is a 2-byte unsigned integer that
@ -3453,7 +3488,8 @@ There are seven time-related functions:
png_convert_to_rfc_1123() in png.c
(formerly png_convert_to_rfc_1152() in error)
png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
png_convert_from_struct_tm() in pngwrite.c, called
in pngwrite.c
png_convert_from_time_t() in pngwrite.c
png_get_tIME() in pngget.c
png_handle_tIME() in pngrutil.c, called in pngread.c
@ -3492,43 +3528,63 @@ 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 png.h shared-lib
version string int version
------- ------ ----- ----------
0.89c ("1.0 beta 3") 0.89 89 1.0.89
0.90 ("1.0 beta 4") 0.90 90 0.90 [should have been 2.0.90]
0.95 ("1.0 beta 5") 0.95 95 0.95 [should have been 2.0.95]
0.96 ("1.0 beta 6") 0.96 96 0.96 [should have been 2.0.96]
0.97b ("1.00.97 beta 7") 1.00.97 97 1.0.1 [should have been 2.0.97]
0.97c 0.97 97 2.0.97
0.98 0.98 98 2.0.98
0.99 0.99 98 2.0.99
0.99a-m 0.99 99 2.0.99
1.00 1.00 100 2.1.0 [100 should be 10000]
1.0.0 1.0.0 100 2.1.0 [100 should be 10000]
1.0.1 1.0.1 10001 2.1.0
1.0.1a-e 1.0.1a-e 10002 2.1.0.1a-e
1.0.2 1.0.2 10002 2.1.0.2
1.0.2a-b 1.0.2a-b 10003 2.1.0.2a-b
1.0.3 1.0.3 10003 2.1.0.3
1.0.3a-d 1.0.3a-d 10004 2.1.0.3a-d
1.0.4 1.0.4 10004 2.1.0.4
1.0.4a-f 1.0.4a-f 10005 2.1.0.4a-f
1.0.5 (+ 2 patches) 1.0.5 10005 2.1.0.5
1.0.5a-d 1.0.5a-d 10006 2.1.0.5a-d
1.0.5e-r 1.0.5e-r 10100 2.1.0.5e-r (not compatible)
1.0.5s-v 1.0.5s-v 10006 2.1.0.5s-v (compatible)
1.0.6 (+ 3 patches) 1.0.6 10006 2.1.0.6
1.0.6d 1.0.6d 10007 2.1.0.6d
1.0.7 1.0.7 10007 2.1.0.7 (still compatible)
source png.h png.h shared-lib
version string int version
------- ------ ----- ----------
0.89c ("beta 3") 0.89 89 1.0.89
0.90 ("beta 4") 0.90 90 0.90
0.95 ("beta 5") 0.95 95 0.95
0.96 ("beta 6") 0.96 96 0.96
0.97b ("beta 7") 1.00.97 97 1.0.1
0.97c 0.97 97 2.0.97
0.98 0.98 98 2.0.98
0.99 0.99 98 2.0.99
0.99a-m 0.99 99 2.0.99
1.00 1.00 100 2.1.0
1.0.0 1.0.0 100 2.1.0
1.0.0 (from here on, the 100 2.1.0
1.0.1 png.h string is 10001 2.1.0
1.0.1a-e identical to the 10002 from here on, the
1.0.2 source version) 10002 shared library is 2.V
1.0.2a-b 10003 where V is the source
1.0.1 10001 code version except as
1.0.1a-e 10002 2.1.0.1a-e noted.
1.0.2 10002 2.1.0.2
1.0.2a-b 10003 2.1.0.2a-b
1.0.3 10003 2.1.0.3
1.0.3a-d 10004 2.1.0.3a-d
1.0.4 10004 2.1.0.4
1.0.4a-f 10005 2.1.0.4a-f
1.0.5 (+ 2 patches) 10005 2.1.0.5
1.0.5a-d 10006 2.1.0.5a-d
1.0.5e-r 10100 2.1.0.5e-r
1.0.5s-v 10006 2.1.0.5s-v
1.0.6 (+ 3 patches) 10006 2.1.0.6
1.0.6d-g 10007 2.1.0.6d-g
1.0.6h 10007 10.6h
1.0.6i 10007 10.6i
1.0.6j 10007 2.1.0.6j
1.0.7beta11-14 DLLNUM 10007 2.1.0.7beta11-14
1.0.7beta15-18 1 10007 2.1.0.7beta15-18
1.0.7rc1-2 1 10007 2.1.0.7rc1-2
1.0.7 1 10007 2.1.0.7
1.0.8beta1-4 1 10008 2.1.0.8beta1-4
1.0.8rc1 1 10008 2.1.0.8rc1
1.0.8 1 10008 2.1.0.8
1.0.9beta1-6 1 10009 2.1.0.9beta1-6
1.0.9rc1 1 10009 2.1.0.9rc1
1.0.9beta7-10 1 10009 2.1.0.9beta7-10
1.0.9rc2 1 10009 2.1.0.9rc2
1.0.9 1 10009 2.1.0.9
1.0.10rc1 1 10010 2.1.0.10rc1
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. The
PNG_PNGLIB_VER macro, which is not used within libpng but is available
for applications, is an unsigned integer of the form xyyzz corresponding
to the source version x.y.z (leading zeros in y and z). Beta versions
are given the previous public release number plus a letter or two.
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. The
PNG_PNGLIB_VER macro, which is not used within libpng but is available
for applications, is an unsigned integer of the form xyyzz corresponding
to the source version x.y.z (leading zeros in y and z). Beta versions
are given the previous public release number plus a letter or two.
.SH "SEE ALSO"
libpngpf(3), png(5)
@ -3576,7 +3632,7 @@ possible without all of you.
Thanks to Frank J. T. Wojcik for helping with the documentation.
Libpng version 1.0.9 - January 31, 2001:
Libpng version 1.0.10beta1 - March 14, 2001:
Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc.
Currently maintained by Glenn Randers-Pehrson (randeg@alum.rpi.edu).
@ -3593,8 +3649,8 @@ included in the libpng distribution, the latter shall prevail.)
If you modify libpng you may insert additional notices immediately following
this sentence.
libpng versions 1.0.7, July 1, 2000, through 1.0.9, January 31, 2001, are
Copyright (c) 2000 Glenn Randers-Pehrson, and are
libpng versions 1.0.7, July 1, 2000, through 1.0.10beta1, March 14, 2001, are
Copyright (c) 2000-2001 Glenn Randers-Pehrson, and are
distributed according to the same disclaimer and license as libpng-1.0.6
with the following individuals added to the list of Contributing Authors
@ -3604,12 +3660,13 @@ with the following individuals added to the list of Contributing Authors
and with the following additions to the disclaimer:
There is no warranty against interference with your enjoyment of the
library or against infringement. There is no warranty that our
efforts or the library will fulfill any of your particular purposes
or needs. This library is provided with all faults, and the entire
risk of satisfactory quality, performance, accuracy, and effort is with
the user.
There is no warranty against interference with your
enjoyment of the library or against infringement.
There is no warranty that our efforts or the library
will fulfill any of your particular purposes or needs.
This library is provided with all faults, and the entire
risk of satisfactory quality, performance, accuracy, and
effort is with the user.
libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
Copyright (c) 1998, 1999 Glenn Randers-Pehrson
@ -3658,11 +3715,11 @@ to the following restrictions:
1. The origin of this source code must not be misrepresented.
2. Altered versions must be plainly marked as such and must not
be misrepresented as being the original source.
2. Altered versions must be plainly marked as such and
must not be misrepresented as being the original source.
3. This Copyright notice may not be removed or altered from any
source or altered source distribution.
3. This Copyright notice may not be removed or altered from
any source or altered source distribution.
The Contributing Authors and Group 42, Inc. specifically permit, without
fee, and encourage the use of this source code as a component to
@ -3684,7 +3741,7 @@ certification mark of the Open Source Initiative.
Glenn Randers-Pehrson
randeg@alum.rpi.edu
January 31, 2001
March 14, 2001
.\" end of man page

236
libpng.txt
View File

@ -1,6 +1,6 @@
libpng.txt - A description on how to use and modify libpng
libpng version 1.0.9 - January 31, 2001
libpng version 1.0.10beta1 - March 14, 2001
Updated and distributed by Glenn Randers-Pehrson
<randeg@alum.rpi.edu>
Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson
@ -257,10 +257,11 @@ input stream. You must supply the function
png_byte name[5];
png_byte *data;
png_size_t size;
/* Note that libpng has already taken care of the
CRC handling */
/* Note that libpng has already taken care of
the CRC handling */
/* put your code here. Return one of the following: */
/* put your code here. Return one of the
following: */
return (-n); /* chunk had an error */
return (0); /* did not recognize */
@ -331,16 +332,23 @@ the entire image into memory, and (b) the input transformations
you want to do are limited to the following set:
PNG_TRANSFORM_IDENTITY No transformation
PNG_TRANSFORM_STRIP_16 Strip 16-bit samples to 8 bits
PNG_TRANSFORM_STRIP_16 Strip 16-bit samples to
8 bits
PNG_TRANSFORM_STRIP_ALPHA Discard the alpha channel
PNG_TRANSFORM_PACKING Expand 1, 2 and 4-bit samples to bytes
PNG_TRANSFORM_PACKSWAP Change order of packed pixels to LSB first
PNG_TRANSFORM_PACKING Expand 1, 2 and 4-bit
samples to bytes
PNG_TRANSFORM_PACKSWAP Change order of packed
pixels to LSB first
PNG_TRANSFORM_EXPAND Perform set_expand()
PNG_TRANSFORM_INVERT_MONO Invert monochrome images
PNG_TRANSFORM_SHIFT Normalize pixels to the sBIT depth
PNG_TRANSFORM_BGR Flip RGB to BGR, RGBA to BGRA
PNG_TRANSFORM_SWAP_ALPHA Flip RGBA to ARGB or GA to AG
PNG_TRANSFORM_INVERT_ALPHA Change alpha from opacity to transparency
PNG_TRANSFORM_SHIFT Normalize pixels to the
sBIT depth
PNG_TRANSFORM_BGR Flip RGB to BGR, RGBA
to BGRA
PNG_TRANSFORM_SWAP_ALPHA Flip RGBA to ARGB or GA
to AG
PNG_TRANSFORM_INVERT_ALPHA Change alpha from opacity
to transparency
PNG_TRANSFORM_SWAP_ENDIAN Byte-swap 16-bit samples
(This excludes setting a background color, doing gamma transformation,
@ -368,9 +376,11 @@ where row_pointers is an array of pointers to the pixel data for each row:
If you know your image size and pixel size ahead of time, you can allocate
row_pointers prior to calling png_read_png() with
row_pointers = png_malloc(png_ptr, height*sizeof(png_bytep));
row_pointers = png_malloc(png_ptr,
height*sizeof(png_bytep));
for (int i=0; i<height, i++)
row_pointers[i]=png_malloc(png_ptr, width*pixel_size);
row_pointers[i]=png_malloc(png_ptr,
width*pixel_size);
png_set_rows(png_ptr, info_ptr, &row_pointers);
Alternatively you could allocate your image in one big block and define
@ -438,8 +448,8 @@ in until png_read_end() has read the chunk data following the image.
interlace_type - (PNG_INTERLACE_NONE or
PNG_INTERLACE_ADAM7)
Any or all of interlace_type, compression_type, of
filter_method can be NULL if you are
not interested in their values.
filter_method can be NULL if you are
not interested in their values.
channels = png_get_channels(png_ptr, info_ptr);
channels - number of channels of info for the
@ -502,14 +512,15 @@ into the info_ptr is returned for any complex types.
implies specific values of gAMA and
cHRM.
png_get_iCCP(png_ptr, info_ptr, &name, &compression_type,
&profile, &proflen);
png_get_iCCP(png_ptr, info_ptr, &name,
&compression_type, &profile, &proflen);
name - The profile name.
compression - The compression type; always PNG_COMPRESSION_TYPE_BASE
for PNG 1.0. You may give NULL to this argument
to ignore it.
profile - International Color Consortium color profile
data. May contain NULs.
compression - The compression type; always
PNG_COMPRESSION_TYPE_BASE for PNG 1.0.
You may give NULL to this argument to
ignore it.
profile - International Color Consortium color
profile data. May contain NULs.
proflen - length of profile data in bytes.
png_get_sBIT(png_ptr, info_ptr, &sig_bit);
@ -565,21 +576,24 @@ into the info_ptr is returned for any complex types.
string for unknown).
text_ptr[i].translated_keyword - keyword in UTF-8
(empty string for unknown).
num_text - number of comments (same as num_comments;
you can put NULL here to avoid the duplication)
Note while png_set_text() will accept text, language, and
translated keywords that can be NULL pointers, the structure
returned by png_get_text will always contain regular
zero-terminated C strings. They might be empty strings but
they will never be NULL pointers.
num_text - number of comments (same as
num_comments; you can put NULL here
to avoid the duplication)
Note while png_set_text() will accept text, language,
and translated keywords that can be NULL pointers, the
structure returned by png_get_text will always contain
regular zero-terminated C strings. They might be
empty strings but they will never be NULL pointers.
num_spalettes = png_get_sPLT(png_ptr, info_ptr, &palette_ptr);
num_spalettes = png_get_sPLT(png_ptr, info_ptr,
&palette_ptr);
palette_ptr - array of palette structures holding
contents of one or more sPLT chunks read.
contents of one or more sPLT chunks
read.
num_spalettes - number of sPLT chunks read.
png_get_oFFs(png_ptr, info_ptr, &offset_x, &offset_y,
&unit_type);
&unit_type);
offset_x - positive offset from the left edge
of the screen
offset_y - positive offset from the top edge
@ -587,7 +601,7 @@ into the info_ptr is returned for any complex types.
unit_type - PNG_OFFSET_PIXEL, PNG_OFFSET_MICROMETER
png_get_pHYs(png_ptr, info_ptr, &res_x, &res_y,
&unit_type);
&unit_type);
res_x - pixels/unit physical resolution in
x direction
res_y - pixels/unit physical resolution in
@ -595,47 +609,50 @@ into the info_ptr is returned for any complex types.
unit_type - PNG_RESOLUTION_UNKNOWN,
PNG_RESOLUTION_METER
png_get_sCAL(png_ptr, info_ptr, &unit, &width, &height)
png_get_sCAL(png_ptr, info_ptr, &unit, &width,
&height)
unit - physical scale units (an integer)
width - width of a pixel in physical scale units
height - height of a pixel in physical scale units
(width and height are doubles)
png_get_sCAL_s(png_ptr, info_ptr, &unit, &width, &height)
png_get_sCAL_s(png_ptr, info_ptr, &unit, &width,
&height)
unit - physical scale units (an integer)
width - width of a pixel in physical scale units
height - height of a pixel in physical scale units
(width and height are strings like "2.54")
num_unknown_chunks = png_get_unknown_chunks(png_ptr, info_ptr,
&unknowns)
unknowns - array of png_unknown_chunk structures holding
unknown chunks
num_unknown_chunks = png_get_unknown_chunks(png_ptr,
info_ptr, &unknowns)
unknowns - array of png_unknown_chunk
structures holding unknown chunks
unknowns[i].name - name of unknown chunk
unknowns[i].data - data of unknown chunk
unknowns[i].size - size of unknown chunk's data
unknowns[i].location - position of chunk in file
The value of "i" corresponds to the order in which the chunks were read
from the PNG file or inserted with the png_set_unknown_chunks() function.
The value of "i" corresponds to the order in which the
chunks were read from the PNG file or inserted with the
png_set_unknown_chunks() function.
The data from the pHYs chunk can be retrieved in several convenient
forms:
res_x = png_get_x_pixels_per_meter(png_ptr,
info_ptr)
info_ptr)
res_y = png_get_y_pixels_per_meter(png_ptr,
info_ptr)
info_ptr)
res_x_and_y = png_get_pixels_per_meter(png_ptr,
info_ptr)
info_ptr)
res_x = png_get_x_pixels_per_inch(png_ptr,
info_ptr)
info_ptr)
res_y = png_get_y_pixels_per_inch(png_ptr,
info_ptr)
info_ptr)
res_x_and_y = png_get_pixels_per_inch(png_ptr,
info_ptr)
info_ptr)
aspect_ratio = png_get_pixel_aspect_ratio(png_ptr,
info_ptr)
info_ptr)
(Each of these returns 0 [signifying "unknown"] if
the data is not present or if res_x is 0;
@ -650,8 +667,8 @@ forms:
y_offset = png_get_y_offset_inches(png_ptr, info_ptr);
(Each of these returns 0 [signifying "unknown" if both
x and y are 0] if the data is not present or if the chunk
is present but the unit is the pixel)
x and y are 0] if the data is not present or if the
chunk is present but the unit is the pixel)
For more information, see the png_info definition in png.h and the
PNG specification for chunk contents. Be careful with trusting
@ -1185,7 +1202,7 @@ When you are done, you can free all memory allocated by libpng like this:
It is also possible to individually free the info_ptr members that
point to libpng-allocated storage with the following function:
png_free_data(png_ptr, info_ptr, mask, n)
png_free_data(png_ptr, info_ptr, mask, seq)
mask - identifies data to be freed, a mask
containing the logical OR of one or
more of
@ -1195,16 +1212,17 @@ point to libpng-allocated storage with the following function:
PNG_FREE_SCAL, PNG_FREE_SPLT,
PNG_FREE_TEXT, PNG_FREE_UNKN,
or simply PNG_FREE_ALL
n - sequence number of item to be freed
seq - sequence number of item to be freed
(-1 for all items)
This function may be safely called when the relevant storage has
already been freed, or has not yet been allocated, or was allocated
by the user and not by libpng, and will in those
cases do nothing. The "n" parameter is ignored if only one item
of the selected data type, such as PLTE, is allowed. If "n" is not
cases do nothing. The "seq" parameter is ignored if only one item
of the selected data type, such as PLTE, is allowed. If "seq" is not
-1, and multiple items are allowed for the data type identified in
the mask, such as text or sPLT, only the n'th item is freed.
the mask, such as text or sPLT, only the n'th item in the structure
is freed, where n is "seq".
The default behavior is only to free data that was allocated internally
by libpng. This can be changed, so that libpng will not free the data,
@ -1377,9 +1395,10 @@ png_infop info_ptr;
/* This function is called when each row of image
data is complete */
void
row_callback(png_structp png_ptr, png_bytep new_row,
png_uint_32 row_num, int pass)
png_uint_32 row_num, int pass)
{
/* If the image is interlaced, and you turned
on the interlace handler, this function will
@ -1523,7 +1542,8 @@ called after each row has been written, which you can use to control
a progress meter or the like. It's demonstrated in pngtest.c.
You must supply a function
void write_row_callback(png_ptr, png_uint_32 row, int pass);
void write_row_callback(png_ptr, png_uint_32 row,
int pass);
{
/* put your code here */
}
@ -1551,8 +1571,9 @@ types.
/* turn on or off filtering, and/or choose
specific filters. You can use either a single PNG_FILTER_VALUE_NAME
or the logical OR of one or more PNG_FILTER_NAME masks. */
specific filters. You can use either a single
PNG_FILTER_VALUE_NAME or the logical OR of one
or more PNG_FILTER_NAME masks. */
png_set_filter(png_ptr, 0,
PNG_FILTER_NONE | PNG_FILTER_VALUE_NONE |
PNG_FILTER_SUB | PNG_FILTER_VALUE_SUB |
@ -1688,11 +1709,12 @@ Some of the more important parts of the png_info are:
png_set_iCCP(png_ptr, info_ptr, name, compression_type,
profile, proflen);
name - The profile name.
compression - The compression type; always PNG_COMPRESSION_TYPE_BASE
for PNG 1.0. You may give NULL to this argument
to ignore it.
profile - International Color Consortium color profile
data. May contain NULs.
compression - The compression type; always
PNG_COMPRESSION_TYPE_BASE for PNG 1.0.
You may give NULL to this argument to
ignore it.
profile - International Color Consortium color
profile data. May contain NULs.
proflen - length of profile data in bytes.
png_set_sBIT(png_ptr, info_ptr, sig_bit);
@ -1746,11 +1768,13 @@ Some of the more important parts of the png_info are:
or empty for unknown).
num_text - number of comments
png_set_sPLT(png_ptr, info_ptr, &palette_ptr, num_spalettes);
palette_ptr - array of png_sPLT_struct structures to be
added to the list of palettes in the info
structure.
num_spalettes - number of palette structures to be added.
png_set_sPLT(png_ptr, info_ptr, &palette_ptr,
num_spalettes);
palette_ptr - array of png_sPLT_struct structures
to be added to the list of palettes
in the info structure.
num_spalettes - number of palette structures to be
added.
png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y,
unit_type);
@ -1781,9 +1805,10 @@ Some of the more important parts of the png_info are:
height - height of a pixel in physical scale units
(width and height are strings like "2.54")
png_set_unknown_chunks(png_ptr, info_ptr, &unknowns, num_unknowns)
unknowns - array of png_unknown_chunk structures holding
unknown chunks
png_set_unknown_chunks(png_ptr, info_ptr, &unknowns,
num_unknowns)
unknowns - array of png_unknown_chunk
structures holding unknown chunks
unknowns[i].name - name of unknown chunk
unknowns[i].data - data of unknown chunk
unknowns[i].size - size of unknown chunk's data
@ -1792,14 +1817,15 @@ Some of the more important parts of the png_info are:
PNG_HAVE_IHDR: before PLTE
PNG_HAVE_PLTE: before IDAT
PNG_AFTER_IDAT: after IDAT
The "location" member is set automatically according to
what part of the output file has already been written.
You can change its value after calling png_set_unknown_chunks()
as demonstrated in pngtest.c. Within each of the "locations",
the chunks are sequenced according to their position in the
structure (that is, the value of "i", which is the order in which
the chunk was either read from the input file or defined with
png_set_unknown_chunks).
The "location" member is set automatically according to
what part of the output file has already been written.
You can change its value after calling png_set_unknown_chunks()
as demonstrated in pngtest.c. Within each of the "locations",
the chunks are sequenced according to their position in the
structure (that is, the value of "i", which is the order in which
the chunk was either read from the input file or defined with
png_set_unknown_chunks).
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.
@ -1900,12 +1926,17 @@ transformations are permitted, enabled by the following masks.
PNG_TRANSFORM_IDENTITY No transformation
PNG_TRANSFORM_PACKING Pack 1, 2 and 4-bit samples
PNG_TRANSFORM_PACKSWAP Change order of packed pixels to LSB first
PNG_TRANSFORM_PACKSWAP Change order of packed
pixels to LSB first
PNG_TRANSFORM_INVERT_MONO Invert monochrome images
PNG_TRANSFORM_SHIFT Normalize pixels to the sBIT depth
PNG_TRANSFORM_BGR Flip RGB to BGR, RGBA to BGRA
PNG_TRANSFORM_SWAP_ALPHA Flip RGBA to ARGB or GA to AG
PNG_TRANSFORM_INVERT_ALPHA Change alpha from opacity to transparency
PNG_TRANSFORM_SHIFT Normalize pixels to the
sBIT depth
PNG_TRANSFORM_BGR Flip RGB to BGR, RGBA
to BGRA
PNG_TRANSFORM_SWAP_ALPHA Flip RGBA to ARGB or GA
to AG
PNG_TRANSFORM_INVERT_ALPHA Change alpha from opacity
to transparency
PNG_TRANSFORM_SWAP_ENDIAN Byte-swap 16-bit samples
PNG_TRANSFORM_STRIP_FILLER Strip out filler bytes.
@ -2169,7 +2200,7 @@ When you are done, you can free all memory used by libpng like this:
It is also possible to individually free the info_ptr members that
point to libpng-allocated storage with the following function:
png_free_data(png_ptr, info_ptr, mask, n)
png_free_data(png_ptr, info_ptr, mask, seq)
mask - identifies data to be freed, a mask
containing the logical OR of one or
more of
@ -2179,16 +2210,17 @@ point to libpng-allocated storage with the following function:
PNG_FREE_SCAL, PNG_FREE_SPLT,
PNG_FREE_TEXT, PNG_FREE_UNKN,
or simply PNG_FREE_ALL
n - sequence number of item to be freed
seq - sequence number of item to be freed
(-1 for all items)
This function may be safely called when the relevant storage has
already been freed, or has not yet been allocated, or was allocated
by the user and not by libpng, and will in those
cases do nothing. The "n" parameter is ignored if only one item
of the selected data type, such as PLTE, is allowed. If "n" is not
cases do nothing. The "seq" parameter is ignored if only one item
of the selected data type, such as PLTE, is allowed. If "seq" is not
-1, and multiple items are allowed for the data type identified in
the mask, such as text or sPLT, only the n'th item is freed.
the mask, such as text or sPLT, only the n'th item in the structure
is freed, where n is "seq".
If you allocated data such as a palette that you passed
in to libpng with png_set_*, you must not free it until just before the call to
@ -2269,8 +2301,8 @@ memory allocation on a platform will change between applications, these
functions must be modified in the library at compile time. If you prefer
to use a different method of allocating and freeing data, you can use
png_set_mem_fn(png_structp png_ptr, png_voidp mem_ptr, png_malloc_ptr
malloc_fn, png_free_ptr free_fn)
png_set_mem_fn(png_structp png_ptr, png_voidp mem_ptr,
png_malloc_ptr malloc_fn, png_free_ptr free_fn)
This function also provides a void pointer that can be retrieved via
@ -2278,7 +2310,8 @@ This function also provides a void pointer that can be retrieved via
Your replacement memory functions must have prototypes as follows:
png_voidp malloc_fn(png_structp png_ptr, png_uint_32 size);
png_voidp malloc_fn(png_structp png_ptr,
png_uint_32 size);
void free_fn(png_structp png_ptr, png_voidp ptr);
Input/Output in libpng is done through png_read() and png_write(),
@ -2490,10 +2523,12 @@ structures appropriately for all of the filter types.
png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE,
filters);
The second parameter can also be PNG_INTRAPIXEL_DIFFERENCING
if you are writing a PNG to be embedded in a MNG
datastream. This parameter must be the same as the
value of filter_method used in png_set_IHDR().
The second parameter can also be
PNG_INTRAPIXEL_DIFFERENCING if you are
writing a PNG to be embedded in a MNG
datastream. This parameter must be the
same as the value of filter_method used
in png_set_IHDR().
It is also possible to influence how libpng chooses from among the
available filters. This is done in two ways - by telling it how
@ -2682,13 +2717,13 @@ application:
VIII. Y2K Compliance in libpng
January 31, 2001
March 14, 2001
Since the PNG Development group is an ad-hoc body, we can't make
an official declaration.
This is your unofficial assurance that libpng from version 0.71 and
upward through 1.0.9 are Y2K compliant. It is my belief that earlier
upward through 1.0.10beta1 are Y2K compliant. It is my belief that earlier
versions were also Y2K compliant.
Libpng only has three year fields. One is a 2-byte unsigned integer that
@ -2706,7 +2741,8 @@ There are seven time-related functions:
png_convert_to_rfc_1123() in png.c
(formerly png_convert_to_rfc_1152() in error)
png_convert_from_struct_tm() in pngwrite.c, called in pngwrite.c
png_convert_from_struct_tm() in pngwrite.c, called
in pngwrite.c
png_convert_from_time_t() in pngwrite.c
png_get_tIME() in pngget.c
png_handle_tIME() in pngrutil.c, called in pngread.c

4
libpngpf.3
View File

@ -1,6 +1,6 @@
.TH LIBPNGPF 3 "January 31, 2001"
.TH LIBPNGPF 3 "March 14, 2001"
.SH NAME
libpng \- Portable Network Graphics (PNG) Reference Library 1.0.9
libpng \- Portable Network Graphics (PNG) Reference Library 1.0.10beta1
(private functions)
.SH SYNOPSIS
\fB#include <png.h>\fP

2
png.5
View File

@ -1,4 +1,4 @@
.TH PNG 5 "January 31, 2001"
.TH PNG 5 "March 14, 2001"
.SH NAME
png \- Portable Network Graphics (PNG) format
.SH DESCRIPTION

14
png.c
View File

@ -1,7 +1,7 @@
/* png.c - location for general purpose libpng functions
*
* libpng version 1.0.9 - January 31, 2001
* libpng version 1.0.10beta1 - March 14, 2001
* Copyright (c) 1998-2001 Glenn Randers-Pehrson
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@ -13,14 +13,14 @@
#include "png.h"
/* Generate a compiler error if there is an old png.h in the search path. */
typedef version_1_0_9 Your_png_h_is_not_version_1_0_9;
typedef version_1_0_10beta1 Your_png_h_is_not_version_1_0_10beta1;
/* Version information for C files. This had better match the version
* string defined in png.h. */
#ifdef PNG_USE_GLOBAL_ARRAYS
/* png_libpng_ver was changed to a function in version 1.0.5c */
const char png_libpng_ver[18] = "1.0.9";
const char png_libpng_ver[18] = "1.0.10beta1";