Marion C. Lineberry

Image Segmentation By Edge Tracing

This paper describes an image segmentation technique that has detection and classification applications in autonomous image analysis systems and compares it with current edge and region-based segmentation techniques. The technique, referred to as directed edge tracing, uses both edge magnitude and direction information to reduce segmentation problems commonly associated with segmenters based on edge thresholding. The edge tracing is carried out by examining pixels in a neighborhood of high probability boundary pixels, making the method locally adaptive to contrast changes along a boundary. No a priori knowledge of the number of segments expected or of the level of contrast between segments is required.

Noise Effects For Edge Operators

Techniques and analyses for improving the signal-to-noise performance of edge detectors are presented. A general edge detection method is developed as a result of the noise analysis, and a wide class of edge detectors is shown to be insensitive to edge orientation. For this class, an optimal design with respect to noise statistics is found and a comparison made between many common edge operators. Edge and noise models characteristic of typical images are presented and used in the analysis of these edge detectors.