Editing Mach bands (section)

{{Short description|Optical illusion}}
{{For|the shock-wave pattern|Mach diamond}}
[[File:Mach bands - animation.gif|thumb|196px|right|Exaggerated contrast between edges of the slightly differing shades of gray appears as soon as they touch]]
[[File:Bandes de mach.PNG|thumb|Along the boundary between adjacent shades of grey in the Mach bands illusion, [[lateral inhibition]] makes the darker area falsely appear even darker and the lighter area falsely appear even lighter.]]

'''Mach bands''' is an [[optical illusion]] named after the physicist [[Ernst Mach]]. It exaggerates the [[contrast (vision)|contrast]] between edges of the slightly differing shades of gray, as soon as they contact one another, by triggering edge-detection in the human visual system. The Mach band illusion is sometimes called the '''Chevreul''' illusion.<ref>{{Cite journal |last=Geier |first=János |last2=Hudák |first2=Mariann |date=2011-10-13 |title=Changing the Chevreul Illusion by a Background Luminance Ramp: Lateral Inhibition Fails at Its Traditional Stronghold - A Psychophysical Refutation |url=https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0026062 |journal=PLoS One |language=en |volume=6 |issue=10 |pages=e26062 |doi=10.1371/journal.pone.0026062 |issn=1932-6203 |pmc=3192777 |pmid=22022508 |doi-access=free}}</ref>