page_title: Posterization
hierarchical_section_title: Posterization
caption_attribution_description: The following is an example of a scenario where posterization may occur, and relates to the image above. A photo saved in JPEG has 256 variations of luminosity in Red, Green and Blue (RGB) in which to derive its colours. This is approximately 16.7 million colours (256*256*256). However, if you were to take this image and save it as a GIF format image, which has a total of only 256 variations of RGB in which to work with, then the subtle transitions in colour and luminosity that your original photo contained may end up in very obvious and aesthetically unpleasing 'jumps' from one shade to another. This is posterization.
context_page_description: Posterization or posterisation of an image entails conversion of a continuous gradation of tone to several regions of fewer tones, with abrupt changes from one tone to another. This was originally done with photographic processes to create posters. It can now be done photographically or with digital image processing, and may be deliberate or an unintended artifact of color quantization.
context_section_description: Posterization or posterisation of an image entails conversion of a continuous gradation of tone to several regions of fewer tones, with abrupt changes from one tone to another.  This was originally done with photographic processes to create posters.  It can now be done photographically or with digital image processing, and may be deliberate or an unintended artifact of color quantization.
caption: 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.
exif: {"Image Orientation": "Horizontal (normal)", "Image XResolution": "72", "Image YResolution": "72", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Adobe Photoshop CS2 Windows", "Image DateTime": "2005:12:08 13:43:20", "Image ExifOffset": "164", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "302", "Thumbnail JPEGInterchangeFormatLength": "5611", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "658", "EXIF ExifImageLength": "894"}