Practical edge finding with a robust estimator

This paper presents a new algorithm for locating the boundaries of textured regions (both step changes and outliers) using a robust estimator. Previous robust image filters perform poorly on binary images, blur edges, round corners, and run slowly. The author avoids artifacts on binary images by modelling them as continuous and interpolating values. Information is combined directly between non-adjacent locations to prevent blurring. Corners are sharpened by relabelling mis-classified pixels. The algorithm is made as fast as a Marr-Hildreth edge finder by restructuring the estimator as a series of 2D image operations, using new multi-ring order statistic operators, and running most of the estimator on a randomly sampled image