Nonlinear point operators for edge detection

In this paper, an edge detection scheme is proposed. This scheme employs a nonlinear point operator, followed by a usual edge detector, e.g. the Sobel edge detector. Three point operator functions are defined and their effects on edge detection are analyzed. The performance of the Sobel edge detector and the nonlinear point operators in the presence of noise is evaluated. Examples of simulated and actual images are given, and the results show that a suitable point operator can improve the edge detection process.