- As the previous luminance staircase is surrounded by a luminance
backround ramp, the inhomogeneity of the steps ceases if the direction of
the luminance change is opposite to that of the background
- On the other hand, when the direction of the luminance change of the
staircase is identical with the luminance change of the ramp, the illusory inhomogenity of the steps are perceived more
intensely than in the original Chevreul Illusion image.
- These effects are generated exclusively by the luminance ramp