Simulation of the neon spreading effect by bandpass filtering

The neon spreading effect has been attentive since the 1970s. It was assumed this kind of illusory spreading of color, resembling the diffuse light that issues from a glowing neon tube, was some stage in one's visual system where a physical process introduces an error. In this paper, the experimental results showed that the brightness difference between grids and crosses was the prior condition for the neon spreading to appear. We proposed that this kind of illusion was the result of the visual image processing, and could be interpreted by bandpass filtering which involved the filters of several spectral widths. The computer simulation on the neon-spreading effect by Gaussian filtering also helps the proposal.