Template matching in pyramids

Abstract Correlation of a small “template” array with a large image array is an operation commonly used in image analysis. Edge detection, line and corner finding are some applications of the technique. Two problems with template matching are its computational cost and its sensitivity to noise. Pyramids (image hierarchies incorporating variable resolution) allow template matching to be performed in a new manner. Hierarchical template matching allows both a savings in computation time (by a problem-dependent amount) and a considerable degree of insensitivity to noise. These techniques are introduced and analyzed through a series of simple and empirical examples. An important feature of template matching locations that would be difficult to enforce and evene to express, in the traditional nonhierarchical framework. The hierarchical approach admits a large variety of image-processing operations.