Edge detection provides a more rigorous means than thresholding for initiating image segmentation. There is a large history of ad hoc edge detection algorithms, and this chapter aims to distinguish what is principled from what is ad hoc, and to provide theory and practical knowledge underpinning available techniques.
Look out for:
• the variety of template matching operators that have been used for edge detection—for example, the Prewitt, Kirsch, and Robinson operators.
• the differential gradient approach to edge detection—exemplified by the Roberts, Sobel, and Frei-Chen operators.
• theory explaining the performance of the template matching operators.
• methods for the optimal design of differential gradient operators, and ...