Normalization (image processing): Difference between revisions

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{{Unreferenced|date=May 2011}}

In [[image processing]], '''normalization''' is a process that changes the range of [[pixel]] intensity values. Applications include photographs with poor [[contrast (vision)|contrast]] due to glare, for example. Normalization is sometimes called contrast stretching. In more general fields of data processing, such as [[digital signal processing]], it is referred to as [[dynamic range]] expansion.<ref>Page{{Cite book| page=85, "Digital image processing" (2008),
author=Rafael C. González, Richard Eugene Woods, Prentice Hall</ref>|

title=Digital Image Processing |

publisher=Prentice Hall |

year=2007 |

IBSN=013168728X

}}</ref>

The purpose of dynamic range expansion in the various applications is usually to bring the image, or other type of signal, into a range that is more familiar or normal to the senses, hence the term normalization. Often, the motivation is to achieve consistency in dynamic range for a set of data, signals, or images to avoid mental distraction or fatigue. For example, a newspaper will strive to make all of the images in an issue share a similar range of [[grayscale]].