What can you see? Michael White designed a brightness illusion in which mid-gray stripes are laid over black and white stripes. Despite their size, the gray tone of the short stripes is influenced by the color of the long stripes. The early history of this Illusion and how he was inspired to investigate it was described by Michael White himself (White, 2010). An explanation of this try Corney & Lotto (2007).

What can you do? Almost all parameters can be changed in the program. So you can reproduce the image above (in high format) and you can examine the influence of single variables or their combination. What influence has the length of the grey stripes, the number of these test elements,  or the spacing of the vertical lines (width)? What effect does the grey tone have, which can be steplessly adjusted from black to white? You can move the vertical lines up and down with y_start. The horizontal and vertical starting points of the short lines can also be moved when needed (only changeable in the code!).

Related topics: White’s illusion with dots, Munker illusion, Bezold effect

References:
Corney D, Lotto RB (2007) What Are Lightness Illusions and Why Do We See Them? PLOS Computational Biology 3(9): e180. Available as download.
White, M. (2010). The Early History of White’s Illusion. Colour: Design & Creativity (5) (2010): 7, 1–7. Available as download.