Editing Posterization (section)

{{Short description|Flaws caused by insufficient color depth}}
{{For|the basketball slang term about dunking over an opponent|Posterized}}
{{More citations needed|date=January 2011}}
[[File:Posterization example.jpg|thumb|Example of a photograph in [[JPEG]] format (24-bit color or 16.7 million colors) before posterization, contrasting the result of saving to [[GIF]] format ([[256 colors]]). Posterization occurs across the image, but is most obvious in areas of subtle variation in tone.]]
[[File:Lucidity I.jpg|thumb|Posterized photo of a [[hibiscus]]]]
[[File:Porträt-isohelie.gif|thumb|Posterized photo]]

'''Posterization''' or '''posterisation''' of an image is the conversion of a continuous gradation of tone to several regions of fewer tones, causing abrupt changes from one tone to another.<ref>{{cite journal |last1=Chao |first1=Cheng-Kang Ted |title=PosterChild: Blend-Aware Artistic Posterization |journal=Computer Graphics Forum |date=15 July 2021 |volume=40 |issue=4 |page=87 |doi=10.1111/cgf.14343 |url=https://cragl.cs.gmu.edu/posterchild/PosterChild-%20Blend-Aware%20Artistic%20Posterization%20(Cheng-Kang%20Ted%20Chao,%20Karan%20Singh,%20Yotam%20Gingold%202021%20EGSR).pdf |access-date=19 April 2024}}</ref> This was originally done with photographic processes to create [[poster]]s. It can now be done photographically or with digital image processing, and may be deliberate or an unintended artifact of [[color quantization]]. Posterization is often the first step in [[Image tracing|vectorization]] (tracing) of an image.