Applications of algebraic moments for edge detection for locally linear model

Abstract

We describe a subpixel edge detection approach in images. The proposed approach is based on the algebraic moments of the brightness function of halftone images. For an ideal two-dimensional edge, we consider a model with the following four parameters: the edge orientation, the distance from the edge to the center of the mask, and the brightness values from both sides of the edge. To obtain all subpixel parameters of the edge, six algebraic moments are used. To compute the moments rapidly, masks are used. The specificity of the proposed approach is as follows: masks of almost all sizes can be used and they are computed by means of explicit relations provided in the present paper as well. Increasing mask sizes, one can increase the accuracy of the detection of subpixel edge parameters, which is especially important for high-definition images. We present experiments displaying the efficiency of the proposed approach.