3 ms·
That was interlaced GIF, see https://en.wikipedia.org/wiki/GIF#Interlacing https://en.wikipedia.org/wiki/GIF#Interlacing (the demo image in the article is from
by zczc 3y ago
That was interlaced GIF, see https://en.wikipedia.org/wiki/GIF#Interlacing https://en.wikipedia.org/wiki/GIF#Interlacing (the demo image in the article is from Chrome which tries to approximate the image with rectangular regions, the 1990s browsers showed not yet received lines as blank which made interlacing effect)