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Diffstat (limited to 'libpng-manual.txt')
| -rw-r--r-- | libpng-manual.txt | 31 |
1 files changed, 18 insertions, 13 deletions
diff --git a/libpng-manual.txt b/libpng-manual.txt index ac0ff1b49..c854b4c68 100644 --- a/libpng-manual.txt +++ b/libpng-manual.txt @@ -1,9 +1,9 @@ libpng-manual.txt - A description on how to use and modify libpng - libpng version 1.6.8 - December 19, 2013 + libpng version 1.6.9 - February 6, 2014 Updated and distributed by Glenn Randers-Pehrson <glennrp at users.sourceforge.net> - Copyright (c) 1998-2013 Glenn Randers-Pehrson + Copyright (c) 1998-2014 Glenn Randers-Pehrson This document is released under the libpng license. For conditions of distribution and use, see the disclaimer @@ -11,9 +11,9 @@ libpng-manual.txt - A description on how to use and modify libpng Based on: - libpng versions 0.97, January 1998, through 1.6.8 - December 19, 2013 + libpng versions 0.97, January 1998, through 1.6.9 - February 6, 2014 Updated and distributed by Glenn Randers-Pehrson - Copyright (c) 1998-2013 Glenn Randers-Pehrson + Copyright (c) 1998-2014 Glenn Randers-Pehrson libpng 1.0 beta 6 version 0.96 May 28, 1997 Updated and distributed by Andreas Dilger @@ -4393,6 +4393,9 @@ png_set_error_fn(), which is essentially the same function, but with a new name to force compilation errors with applications that try to use the old method. +Support for the sCAL, iCCP, iTXt, and sPLT chunks was added at libpng-1.0.6; +however, iTXt support was not enabled by default. + Starting with version 1.0.7, you can find out which version of the library you are using at run-time: @@ -4621,6 +4624,7 @@ XI. Changes to Libpng from version 1.4.x to 1.5.x From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the function) incorrectly returned a value of type png_uint_32. +The incorrect macro was removed from libpng-1.4.5. Checking for invalid palette index on write was added at libpng 1.5.10. If a pixel contains an invalid (out-of-range) index libpng issues @@ -4725,7 +4729,10 @@ and the accuracy of PNG fixed point values is insufficient for representation of these values. Consequently a "string" API (png_get_sCAL_s and png_set_sCAL_s) is the only reliable way of reading arbitrary sCAL chunks in the absence of either the floating point API or -internal floating point calculations. +internal floating point calculations. Starting with libpng-1.5.0, both +of these functions are present when PNG_sCAL_SUPPORTED is defined. Prior +to libpng-1.5.0, their presence also depended upon PNG_FIXED_POINT_SUPPORTED +being defined and PNG_FLOATING_POINT_SUPPORTED not being defined. Applications no longer need to include the optional distribution header file pngusr.h or define the corresponding macros during application @@ -4745,11 +4752,6 @@ reset by pngusr.h or by explicit settings on the compiler command line. These settings may produce compiler warnings or errors in 1.5.0 because of macro redefinition. -From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the -function) incorrectly returned a value of type png_uint_32. libpng 1.5.0 -is consistent with the implementation in 1.4.5 and 1.2.x (where the macro -did not exist.) - Applications can now choose whether to use these macros or to call the corresponding function by defining PNG_USE_READ_MACROS or PNG_NO_USE_READ_MACROS before including png.h. Notice that this is @@ -4767,7 +4769,10 @@ option was off by default, and slightly inaccurate scaling occurred. This option can no longer be turned off, and the choice of accurate or inaccurate 16-to-8 scaling is by using the new png_set_scale_16_to_8() API for accurate scaling or the old png_set_strip_16_to_8() API for simple -chopping. +chopping. In libpng-1.5.4, the PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED +macro became PNG_READ_SCALE_16_TO_8_SUPPORTED, and the PNG_READ_16_TO_8 +macro became PNG_READ_STRIP_16_TO_8_SUPPORTED, to enable the two +png_set_*_16_to_8() functions separately. Prior to libpng-1.5.4, the png_set_user_limits() function could only be used to reduce the width and height limits from the value of @@ -5233,13 +5238,13 @@ Other rules can be inferred by inspecting the libpng source. XVI. Y2K Compliance in libpng -December 19, 2013 +February 6, 2014 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 1.6.8 are Y2K compliant. It is my belief that earlier +upward through 1.6.9 are Y2K compliant. It is my belief that earlier versions were also Y2K compliant. Libpng only has two year fields. One is a 2-byte unsigned integer |