Technical Reports (CIS)
Document Type
Technical Report
Date of this Version
February 1994
Abstract
A novel edge operator is introduced based on steerable asymmetric linear filters consisting of radial wedge segments. An intensity profile is computed by averaging intensity values along a radial wedge segment as it "sweeps" about a small circular neighborhood. The "steerability" of the filters allows for interpolation of a continuous profile function for n discretely sampled postions of the radial wedge segments. Edge strength is then calculated as a simple difference of conditinal means of the resulting intensity profile. This paper introduces the basic paradigm of using asymmetric filters for low-level image processing tasks and shows how this approach is utilized to design a novel edge operator (the Radial InTensity Edge, or RITE, operator). Features of the RITE operator include: (1) a mathematically simple algorithm with comparable performance to the well-known gradient-based Deriche operator; (2) better performance at points where several edges intersect; (3) an average time complexity reduction by a factor of 1.7 to 2.1 over the Deriche operator.
Keywords
edge detection, steerable filters, asymmetric filters
Recommended Citation
Gregory Provan, Hany Farid, and Eero Simoncelli, "A Novel Radial Intensity Based Edge Operator", . February 1994.
Date Posted: 16 July 2007
Comments
University of Pennsylvania Department of Computer and Information Science Technical Report No. MS-CIS-94-07.