'''UsmailAliyi9 15@gmail.comEdge detection''' includes a variety of [[mathematical]] methods that aim at identifying '''edges''', [[curve]]s in a [[digital image]] at which the [[luminous intensity|image brightness]] changes sharply or, more formally, has [[Discontinuity (mathematics)|discontinuities]]. The same problem of finding discontinuities in one-dimensional signals is known as ''[[step detection]]'' and the problem of finding signal discontinuities over time is known as ''[[change detection]]''. Edge detection is a fundamental tool in [[image processing]], [[machine vision]] and [[computer vision]], particularly in the areas of [[feature detection (computer vision)|feature detection]] and [[feature extraction]].<ref>{{cite book|last=Umbaugh|first=Scott E|title=Digital image processing and analysis : human and computer vision applications with CVIPtools|year=2010|publisher=CRC Press|___location=Boca Raton, FL|isbn=978-1-4398-0205-2|edition=2nd}}</ref>
