
OptiPNG - Revision history
==========================

Legend
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+ Added or improved feature.
- Removed feature.
* Modified code (e.g. for architectural improvements).
! Fixed bug.


Version 0.4.3	12-aug-2003
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! Fixed a reduction problem that caused an assertion failure.
  (Thanks to Dimitri Papadopoulos for the report.)


Version 0.4.2	30-jun-2003
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+ Enhanced the support for palette size reductions:
  trailing sterile palette entries are removed even when
  the bit depth is below 8.
! Enforced recompression when the new IDAT has the same size,
  but other chunks have been reduced.
+ Displayed the IDAT size difference as a percentage.
  (Thanks to Nehal Mistry for the suggestion.)


Version 0.4.1	19-may-2003
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! Fixed the removal of trailing sterile palette entries.


Version 0.4	12-may-2003
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+ Added support for palette-to-gray reductions.
+ Added partial support for palette size reductions.
! Fixed the reporting of invalid command-line options.
! Eliminated a spurious warning when the zlib window size is set
  to 256.


Version 0.3.2	11-mar-2003
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+ Added support for updating sBIT during reductions.
! Fixed the reduction of the alpha channel.


Version 0.3.1	25-feb-2003
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! Fixed the encoding of interlaced images when they become bigger
  than the input.
+ Added the HISTORY document (this file).


Version 0.3	24-feb-2003
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This is the first public release of OptiPNG.
+ Added support for iterating through zlib memory levels.
+ Added support for collapsing IDAT, avoiding calls to
  png_set_compression_buffer_size().
  This reduces the memory requirements.
+ Added support for lossless reduction of the image type:
  RGB[A] -> G[A], RGBA -> RGB, GA -> G
+ Added many user options.
+ Added documentation.


Version 0.2	27-dec-2001
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+ Added support for optimization level presets.
+ Added user option for changing the interlacing.


Version 0.1	17-dec-2001
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+ Added support for chunk I/O status annotation.
  This improves the speed of OptiPNG significantly.
* Structured exception handling is provided by cexcept.


Version 0.0	10-dec-2001
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This is the very first version of OptiPNG.
It compresses IDAT repeatedly, iterating through zlib compression
and strategy levels, and PNG filters.

