Shape

Here is an exploration of shape perception and the contribution of luminance, again with voiceover, another video letter to a colleague. The point is that explicit shapes can be seen quite well even when defined by equiluminous patterns — here texture is used to demonstrate recovery of 3D structure from motion at equiluminance. But only if the shape is defined by a contiguous region — no missing, interpolated, or amodally completed parts please. If the shape has to be integrated across different surface qualities, it only works when luminance is present. The examples in this case include a rotating paper clip and a randomly checkered square moving smoothly across a similar background.

Luminance, what is it good for?