Edge enhancement

Edge enhancement is an image processing filter that enhances the edge contrast of an image or video in an attempt to improve its acutance (apparent sharpness). Edge enhancement is an image processing filter that enhances the edge contrast of an image or video in an attempt to improve its acutance (apparent sharpness). The filter works by identifying sharp edge boundaries in the image, such as the edge between a subject and a background of a contrasting color, and increasing the image contrast in the area immediately around the edge. This has the effect of creating subtle bright and dark highlights on either side of any edges in the image, called overshoot and undershoot, leading the edge to look more defined when viewed from a typical viewing distance. The process is prevalent in the video field, appearing to some degree in the majority of TV broadcasts and DVDs. A modern television set's 'sharpness' control is an example of edge enhancement. It is also widely used in computer printers especially for font or/and graphics to get a better printing quality. Most digital cameras also perform some edge enhancement, which in some cases cannot be adjusted.