Image Filter Definition | GIS Dictionary

image filter

[image processing] A computing technique by which the size, colors, shading, and other characteristics of an image are altered. Typically uses an <n x n> matrix of weights. The resulting calculation to each output pixel is restricted to the size of the matrix, referred to as a kernel. Image filters are used primarily in pixel-based analysis where the value of a center pixel is changed to the mean, sum, or other function of all pixel values within the filter. Image filters move systematically across a raster until each pixel has been processed.