libpng-manual.txt - A description on how to use and modify libpng
- libpng version 1.5.6 - November 3, 2011
+ libpng version 1.5.7 - December 15, 2011
Updated and distributed by Glenn Randers-Pehrson
<glennrp at users.sourceforge.net>
Copyright (c) 1998-2011 Glenn Randers-Pehrson
Based on:
- libpng versions 0.97, January 1998, through 1.5.6 - November 3, 2011
+ libpng versions 0.97, January 1998, through 1.5.7 - December 15, 2011
Updated and distributed by Glenn Randers-Pehrson
Copyright (c) 1998-2011 Glenn Randers-Pehrson
(empty string for unknown).
Note that the itxt_length, lang, and lang_key
- members of the text_ptr structure only exist
- when the library is built with iTXt chunk support.
- Prior to libpng-1.4.0, the default build was
- without iTXt chunk support.
+ members of the text_ptr structure only exist when the
+ library is built with iTXt chunk support. Prior to
+ libpng-1.4.0 the library was built by default without
+ iTXt support. Also note that when iTXt is supported,
+ they contain NULL pointers when the "compression"
+ field contains PNG_TEXT_COMPRESSION_NONE or
+ PNG_TEXT_COMPRESSION_zTXt.
num_text - number of comments (same as
num_comments; you can put NULL here
empty for unknown).
text_ptr[i].translated_keyword - keyword in UTF-8 (NULL
or empty for unknown).
+
Note that the itxt_length, lang, and lang_key
- members of the text_ptr structure only exist
- when the library is built with iTXt chunk support.
- Prior to libpng-1.4.0 the library was built by default
- without iTXt support.
+ members of the text_ptr structure only exist when the
+ library is built with iTXt chunk support. Prior to
+ libpng-1.4.0 the library was built by default without
+ iTXt support. Also note that when iTXt is supported,
+ they contain NULL pointers when the "compression"
+ field contains PNG_TEXT_COMPRESSION_NONE or
+ PNG_TEXT_COMPRESSION_zTXt.
num_text - number of comments
XIV. Y2K Compliance in libpng
-November 3, 2011
+December 15, 2011
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 1.5.6 are Y2K compliant. It is my belief that earlier
+upward through 1.5.7 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