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Lightness and shape Demonstration#

Lightness and shape

The gradually shaded left and right halves of the flat object on the left are physically identical. The central regions of the left and right cylinders on the right also have identical intensity profiles. Further, all four of gradients are identical to across the central regions. The horizontal light intensity profiles are illustrated by the red lines. 1


  1. David C Knill and Daniel Kersten. Apparent surface curvature affects lightness perception. Nature, 351(6323):228–230, 1991. doi:10.1038/351228a0


Last update: March 3, 2022