/* png.h - header file for PNG reference library * * libpng version 1.2.8 - December 3, 2004 * Copyright (c) 1998-2004 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.) * * Authors and maintainers: *  libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat *  libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger *  libpng versions 0.97, January 1998, through 1.2.8 - December 3, 2004: Glenn *  See also "Contributing Authors", below. * * 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  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      (from here on, the   100  2.1.0 [100 should be 10000] *    1.0.1       png.h string is   10001  2.1.0 *    1.0.1a-e    identical to the  10002  from here on, the shared library *    1.0.2       source version)   10002  is 2.V where V is the source code *    1.0.2a-b                      10003  version, except as noted. *    1.0.3                         10003 *    1.0.3a-d                      10004 *    1.0.4                         10004 *    1.0.4a-f                      10005 *    1.0.5 (+ 2 patches)           10005 *    1.0.5a-d                      10006 *    1.0.5e-r                      10100 (not source compatible) *    1.0.5s-v                      10006 (not binary compatible) *    1.0.6 (+ 3 patches)           10006 (still binary incompatible) *    1.0.6d-f                      10007 (still binary incompatible) *    1.0.6g                        10007 *    1.0.6h                        10007  10.6h (testing xy.z so-numbering) *    1.0.6i                        10007  10.6i *    1.0.6j                        10007  2.1.0.6j (incompatible with 1.0.0) *    1.0.7beta11-14        DLLNUM  10007  2.1.0.7beta11-14 (binary compatible) *    1.0.7beta15-18           1    10007  2.1.0.7beta15-18 (binary compatible) *    1.0.7rc1-2               1    10007  2.1.0.7rc1-2 (binary compatible) *    1.0.7                    1    10007  (still compatible) *    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 *    1.0.10beta1              1    10010  2.1.0.10beta1 *    1.0.10rc1                1    10010  2.1.0.10rc1 *    1.0.10                   1    10010  2.1.0.10 *    1.0.11beta1-3            1    10011  2.1.0.11beta1-3 *    1.0.11rc1                1    10011  2.1.0.11rc1 *    1.0.11                   1    10011  2.1.0.11 *    1.0.12beta1-2            2    10012  2.1.0.12beta1-2 *    1.0.12rc1                2    10012  2.1.0.12rc1 *    1.0.12                   2    10012  2.1.0.12 *    1.1.0a-f                 -    10100  2.1.1.0a-f (branch abandoned) *    1.2.0beta1-2             2    10200  2.1.2.0beta1-2 *    1.2.0beta3-5             3    10200  3.1.2.0beta3-5 *    1.2.0rc1                 3    10200  3.1.2.0rc1 *    1.2.0                    3    10200  3.1.2.0 *    1.2.1beta1-4             3    10201  3.1.2.1beta1-4 *    1.2.1rc1-2               3    10201  3.1.2.1rc1-2 *    1.2.1                    3    10201  3.1.2.1 *    1.2.2beta1-6            12    10202  12.so.0.1.2.2beta1-6 *    1.0.13beta1             10    10013  10.so.0.1.0.13beta1 *    1.0.13rc1               10    10013  10.so.0.1.0.13rc1 *    1.2.2rc1                12    10202  12.so.0.1.2.2rc1 *    1.0.13                  10    10013  10.so.0.1.0.13 *    1.2.2                   12    10202  12.so.0.1.2.2 *    1.2.3rc1-6              12    10203  12.so.0.1.2.3rc1-6 *    1.2.3                   12    10203  12.so.0.1.2.3 *    1.2.4beta1-3            13    10204  12.so.0.1.2.4beta1-3 *    1.0.14rc1               13    10014  10.so.0.1.0.14rc1 *    1.2.4rc1                13    10204  12.so.0.1.2.4rc1 *    1.0.14                  10    10014  10.so.0.1.0.14 *    1.2.4                   13    10204  12.so.0.1.2.4 *    1.2.5beta1-2            13    10205  12.so.0.1.2.5beta1-2 *    1.0.15rc1-3             10    10015  10.so.0.1.0.15rc1-3 *    1.2.5rc1-3              13    10205  12.so.0.1.2.5rc1-3 *    1.0.15                  10    10015  10.so.0.1.0.15 *    1.2.5                   13    10205  12.so.0.1.2.5 *    1.2.6beta1-4            13    10206  12.so.0.1.2.6beta1-4 *    1.0.16                  10    10016  10.so.0.1.0.16 *    1.2.6                   13    10206  12.so.0.1.2.6 *    1.2.7beta1-2            13    10207  12.so.0.1.2.7beta1-2 *    1.0.17rc1               10    10017  12.so.0.1.0.17rc1 *    1.2.7rc1                13    10207  12.so.0.1.2.7rc1 *    1.0.17                  10    10017  12.so.0.1.0.17 *    1.2.7                   13    10207  12.so.0.1.2.7 *    1.2.8beta1-5            13    10208  12.so.0.1.2.8beta1-5 *    1.0.18rc1-5             10    10018  12.so.0.1.0.18rc1-5 *    1.2.8rc1-5              13    10208  12.so.0.1.2.8rc1-5 *    1.0.18                  10    10018  12.so.0.1.0.18 *    1.2.8                   13    10208  12.so.0.1.2.8 * *    Henceforth the source version will match the shared-library major *    and minor numbers; the shared-library major version number will be *    used for changes in backward compatibility, as it is intended.  The *    PNG_LIBPNG_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 *    were given the previous public release number plus a letter, until *    version 1.0.6j; from then on they were given the upcoming public *    release number plus "betaNN" or "rcN". * *    Binary incompatibility exists only when applications make direct access *    to the info_ptr or png_ptr members through png.h, and the compiled *    application is loaded with a different version of the library. * *    DLLNUM will change each time there are forward or backward changes *    in binary compatibility (e.g., when a new feature is added). * * See libpng.txt or libpng.3 for more information.  The PNG specification * is available as a W3C Recommendation and as an ISO Specification, * <http://www.w3.org/TR/2003/REC-PNG-20031110/ *//* * COPYRIGHT NOTICE, DISCLAIMER, and LICENSE: * * If you modify libpng you may insert additional notices immediately following * this sentence. * * libpng versions 1.2.6, August 15, 2004, through 1.2.8, December 3, 2004, are * Copyright (c) 2004 Glenn Randers-Pehrson, and are * distributed according to the same disclaimer and license as libpng-1.2.5 * with the following individual added to the list of Contributing Authors: * *    Cosmin Truta * * libpng versions 1.0.7, July 1, 2000, through 1.2.5, October 3, 2002, are * Copyright (c) 2000-2002 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: * *    Simon-Pierre Cadieux *    Eric S. Raymond *    Gilles Vollant * * 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. * * libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are * Copyright (c) 1998, 1999, 2000 Glenn Randers-Pehrson, and are * distributed according to the same disclaimer and license as libpng-0.96, * with the following individuals added to the list of Contributing Authors: * *    Tom Lane *    Glenn Randers-Pehrson *    Willem van Schaik * * libpng versions 0.89, June 1996, through 0.96, May 1997, are * Copyright (c) 1996, 1997 Andreas Dilger * Distributed according to the same disclaimer and license as libpng-0.88, * with the following individuals added to the list of Contributing Authors: * *    John Bowler *    Kevin Bracey *    Sam Bushell *    Magnus Holmgren *    Greg Roelofs *    Tom Tanner * * libpng versions 0.5, May 1995, through 0.88, January 1996, are * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. * * For the purposes of this copyright and license, "Contributing Authors" * is defined as the following set of individuals: * *    Andreas Dilger *    Dave Martindale *    Guy Eric Schalnat *    Paul Schmidt *    Tim Wegner * * The PNG Reference Library is supplied "AS IS".  The Contributing Authors * and Group 42, Inc. disclaim all warranties, expressed or implied, * including, without limitation, the warranties of merchantability and of * fitness for any purpose.  The Contributing Authors and Group 42, Inc. * assume no liability for direct, indirect, incidental, special, exemplary, * or consequential damages, which may result from the use of the PNG * Reference Library, even if advised of the possibility of such damage. * * Permission is hereby granted to use, copy, modify, and distribute this * source code, or portions hereof, for any purpose, without fee, subject * 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. * * 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 * supporting the PNG file format in commercial products.  If you use this * source code in a product, acknowledgment is not required but would be * appreciated. *//* * A "png_get_copyright" function is available, for convenient use in "about" * boxes and the like: * * printf("%s",png_get_copyright(NULL)); * * Also, the PNG logo (in PNG format, of course) is supplied in the * files "pngbar.png" and "pngbar.jpg (88x31) and "pngnow.png" (98x31). *//* * Libpng is OSI Certified Open Source Software.  OSI Certified is a * certification mark of the Open Source Initiative. *//* * The contributing authors would like to thank all those who helped * with testing, bug fixes, and patience.  This wouldn't have been * possible without all of you. * * Thanks to Frank J. T. Wojcik for helping with the documentation. *//* * Y2K compliance in libpng: * ========================= * *    December 3, 2004 * *    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 1.2.8 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 will hold years up to 65535.  The other two hold the date in text *    format, and will hold years up to 9999. * *    The integer is *        "png_uint_16 year" in png_time_struct. * *    The strings are *        "png_charp time_buffer" in png_struct and *        "near_time_buffer", which is a local character string in png.c. * *    There are seven time-related functions: *        png.c: 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_time_t() in pngwrite.c *        png_get_tIME() in pngget.c *        png_handle_tIME() in pngrutil.c, called in pngread.c *        png_set_tIME() in pngset.c *        png_write_tIME() in pngwutil.c, called in pngwrite.c * *    All handle dates properly in a Y2K environment.  The *    png_convert_from_time_t() function calls gmtime() to convert from system *    clock time, which returns (year - 1900), which we properly convert to *    the full 4-digit year.  There is a possibility that applications using *    libpng are not passing 4-digit years into the png_convert_to_rfc_1123() *    function, or that they are incorrectly passing only a 2-digit year *    instead of "year - 1900" into the png_convert_from_struct_tm() function, *    but this is not under our control.  The libpng documentation has always *    stated that it works with 4-digit years, and the APIs have been *    documented as such. * *    The tIME chunk itself is also Y2K compliant.  It uses a 2-byte unsigned *    integer to hold the year, and can hold years as large as 65535. * *    zlib, upon which libpng depends, is also Y2K compliant.  It contains *    no date-related code.