ace-dent / pngslim Goto Github PK

Roadmap meta issue for security hardening, robustness and related issues.

• #2
• Check image dimensions to defend against deflate 'bombs'.
• [ ]

Alter the RGB values for full transparent pixels (A=0), for improved compression. This is a lossy process and not

• Add option for cleaning transparency. (Default is off).
• Test using simply colours (black, etc.) to enable colour mode reductions (indexed, RGB+trns, G+trns).
• Use tools for more advanced RGB values (optimal for RGBA with filtering).
• Evaluate if this impacts packaging of the resulting png (e.g. worse compression in zip archives).
• Update documentation.

Ensure order of trialling row filters, will prefer desirable filters by testing first.

• Select order based on minimising disk writes. Look at white paper on filter distribution; test most effective first.
• Also consider reducing use of 3 Average and 4 Paeth which are slowest to decode.