Colour banding is a subtle form of posterization in digital images, caused by the colour of each pixel being rounded to the nearest of the digital colour levels. While posterization is often done for artistic effect, colour banding is an undesired artifact. In 24-bit colour modes, 8 bits per channel is usually considered sufficient to render images in Rec. 709 or sRGB. However the eye can see the difference between the colour levels, especially when there is a sharp border between two large areas of adjacent colour levels. This will happen with gradual gradients (like sunsets, dawns or clear blue skies), and also when blurring an image a large amount.
An example of colour banding, visible in the sky in this photographAn illustration of colour banding. Only 3 bits are used for the red channel in the left two images, 8 bits in the right image.
Colour banding is more noticeable with fewer bits per pixel (BPP) at 16–256 colours (4–8 BPP), where there are fewer shades with a larger difference between them.
Possible solutions include the introduction of dithering and increasing the number of bits per colour channel.
Because the banding comes from limitations in the presentation of the image, blurring the image does not fix this.
colour, banding, this, article, does, cite, sources, please, help, improve, this, article, adding, citations, reliable, sources, unsourced, material, challenged, removed, find, sources, news, newspapers, books, scholar, jstor, 2013, learn, when, remove, this, . This article does not cite any sources Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Colour banding news newspapers books scholar JSTOR May 2013 Learn how and when to remove this message Colour banding is a subtle form of posterization in digital images caused by the colour of each pixel being rounded to the nearest of the digital colour levels While posterization is often done for artistic effect colour banding is an undesired artifact In 24 bit colour modes 8 bits per channel is usually considered sufficient to render images in Rec 709 or sRGB However the eye can see the difference between the colour levels especially when there is a sharp border between two large areas of adjacent colour levels This will happen with gradual gradients like sunsets dawns or clear blue skies and also when blurring an image a large amount An example of colour banding visible in the sky in this photograph An illustration of colour banding Only 3 bits are used for the red channel in the left two images 8 bits in the right image Colour banding is more noticeable with fewer bits per pixel BPP at 16 256 colours 4 8 BPP where there are fewer shades with a larger difference between them Possible solutions include the introduction of dithering and increasing the number of bits per colour channel Because the banding comes from limitations in the presentation of the image blurring the image does not fix this See also editPosterization Quantization signal processing External links editDynamic range 24 vs 36 bit nbsp This computing article is a stub You can help Wikipedia by expanding it vte Retrieved from https en wikipedia org w index php title Colour banding amp oldid 1210321034, wikipedia, wiki, book, books, library,
