png.md

PNG

• Hello, PNG!

  • A complete implementation of PNG1.0 spec in a few lines of code. Breaks down headers
  • PNG has lasted because
    • It's "Good enough" at lossless image compression.
    • It builds on existing technologies (zlib/DEFLATE compression).
    • It's simple to implement (helped by the above point).
    • It supports a variety of modes and bit-depths, including "true color" (24-bit RGB) and transparency.
    • It isn't patented.

• The smallest 256x256 single-color PNG file, and where you've seen it

  • #huffman #rle

• ‘optiPNG’ vs ‘PNGcrush’ vs ‘Gimp’ to Reduce PNG Size

• https://optipng.sourceforge.net/

• cICP in PNG, explained 2025

  • New addition to the PNG spec for the first time in 20 years.
  • Massively expanding the color space, by backwards compatible adding to new compressed blocks. Genius.