Using angular dispersion of gradient direction for detecting edge ribbons
- 1 July 1993
- journal article
- Published by Institute of Electrical and Electronics Engineers (IEEE)
- Vol. 15 (7) , 682-696
- https://doi.org/10.1109/34.221169
Abstract
Edges in a scene generally project to smooth continuous curves nearly everywhere in the image, which results in low angular deviation of the intensity gradients in small neighborhoods straddling edges. Angular deviation is shown to be a measure of SNR. A theoretical analysis of angular deviation arising due to independent and identically distributed N(0, sigma /sup 2/) random noise is presented. Angular deviation thresholds for neighborhood sizes from 3*3 to 11*11 pixels are determined both from this analysis and numerical examples. The proposed gradient angular dispersion detection algorithm detects edge elements by comparing the measured angular deviation with values computed for the minimum acceptable SNR. Low values of deviation violate the 'no edge' hypothesis. The algorithm is shown to make good use of the limited dynamic range of the imaging system. The sensitivity and selectivity of the strategy are both shown to be high.Keywords
This publication has 7 references indexed in Scilit:
- Radial projection: an efficient update rule for relaxation labelingPublished by Institute of Electrical and Electronics Engineers (IEEE) ,1989
- Precision edge contrast and orientation estimationPublished by Institute of Electrical and Electronics Engineers (IEEE) ,1988
- The effect of noise on edge orientation computationsPattern Recognition Letters, 1987
- A Computational Approach to Edge DetectionPublished by Institute of Electrical and Electronics Engineers (IEEE) ,1986
- Spatial filters and the localization of luminance changes in human visionVision Research, 1984
- An Application of Relaxation Labeling to Line and Curve EnhancementIEEE Transactions on Computers, 1977
- Scene Labeling by Relaxation OperationsIEEE Transactions on Systems, Man, and Cybernetics, 1976