Colour Science & Perception
what the eye settles, and what it cannot
Generator

The Cornsweet edge, with its luminance profile

The two plateaux are both #898989 and are flat to exactly — the profile below shows that everything which differs lies within a narrow band at the boundary. Cover the centre line and the two halves become obviously identical.
The Cornsweet edge, with its luminance profileThe two plateaux are both #898989 and are flat to exactly — the profile below shows that everything which differs lies within a narrow band at the boundary. Cover the centre line and the two halves become obviously identical.one value on the left, the same value on the rightluminance profileboth plateaux are #898989checked equal

Drawn at its defaults, in what the brain does that the numbers do not. It takes 2 options, and the essays below show what each placement asks of it.

Called by 1 essay

the blast radius of changing it

What the brain does

Brightness is inferred from edges

The Cornsweet effect makes two identical regions look different by altering nothing except a narrow band at the boundary between them. Cover the boundary and the difference vanishes, which says the visual system is reconstructing surfaces rather than reading off intensities.

All 155 generators · what each essay asks for instead