- Fix all defects (duh!)
- cHRM transformation.
- Palette creation.
- "grayscale->palette" transformation and "palette->grayscale" detection.
- Improved dithering.
- Multi-lingual error and warning message support.
- Complete sRGB transformation. (Currently it simply uses gamma=0.45455.)
- Man pages for function calls.
- Better documentation.
- Better filter selection (e.g., counting huffman bits/precompression; filter inertia; filter costs).
- Histogram creation.
- Text conversion between different code pages (e.g., Latin-1 to Mac).
- Avoid building gamma tables whenever possible.
- Greater precision in changing to linear gamma for compositing against background, and in doing rgb-to-gray transformations.
- Investigate pre-incremented loop counters and other loop constructions.
- Interpolated method of handling interlacing.
- More validations for libpng transformations.