Image transcription: Rows of black and white zigzag patterns forming 2x2 checkerboards on a grey background create an optical illusion of warping and motion.
(Originally published on mastodon.social: 2024-02-16)
If you get out an image editor and compare where the pixels fade to the background grey, they are nearly, but not pixel perfect to the same height on the peaks of each row. Different peaks come to different heights. The darker shaded top left ones come up 2 pixels higher than the light ones.
Saying they're perfectly horizontal is slightly misleading. A sawtooth wave on a oscilloscope is perfectly horizontal also. Technically correct, but also omitting some key detail.
Does it mean anything if they aren't moving for me, unless I scroll the image up and down? I've been told that I have field independent vision: I see parts before the whole.
The illusion when moving it up and down does not even break when the picture is very out of focus and viewed with one eye. So there must be something fundamental about the rough shapes and/or color grading. All the fine details are irrelevant.