glitch

Image in, corrupted image out.

Realistic glitches

Glitches that result from corrupted file data.

JPEG

• JPEG wikipedia https://en.wikipedia.org/wiki/JPEG
• JPEG spec https://www.w3.org/Graphics/JPEG/itu-t81.pdf
• JFIF spec https://www.w3.org/Graphics/JPEG/jfif3.pdf

Corrupted entropy data

Current implementation

• find FFDA (start of scan) marker in byte stream, two bytes after that are the length, read and skip those
• until next marker (FFxx, but not FF00)  - skip N bytes, where N random from reasonable range (pay attention to byte stuffing (0xFF00)
  • overwrite 1 byte with
    • slightly different value (e.g. AB->A7)
    • random byte (probably nicer/heaver glitch but gets corrupted more easily)

Better implemenation

Read file twice to figure out start and end of scans, then overwrite N evenly distributed bytes, to avoid the "glitch on top and rest of image has bad colors" effect.

Portrait of Giovanni Arnolfini and his Wife

Corrupted header data

No idea if feasible or desirable.

Artistic glitches

Format-independent artistic interpretations of corrupted data.

• fractal pixelation spots?
• whatever Pony Island does?