Labeling of curvilinear structure across scales by token grouping

This paper presents an algorithm for labeling curvilinear structure at multiple scales in line drawings and edge images Symbolic CURVE-ELEMENT tokens residing in a spatially-indexed and scale-indexed data structure denote circular arcs fit to image data. Tokens are computed via a small-to-large scale grouping procedure employing a “greedy”, best-first, strategy for choosing the support of new tokens. The resulting image description is rich and redundant in that a given segment of image contour may be described by multiple tokens at different scales, and by more than one token at any given scale. This property facilitates selection and characterization of portions of the image based on local CURVE-ELEMENT attributes. XEROX Xerox Corporation Palo Alto Research Center 3333 Coyote Hill Road Palo Alto, California 94304 LABELING OF CURVILINEAR STRUCTURE ACROSS SCALES BY TOKEN GROUPING Labeling of Curvilinear Structure Across Scales by Token Grouping Abstract This paper presents an algorithm for labeling curvilinear structure at multiple scales in line drawings and edge images. Symbolic CURVE-ELEMENT tokens residing in a spatially-indexed and scale-indexed data structure denote circular arcs fit to image data. Tokens are computed via a small-to-large scale groupj~gprocedure empj~.g_ a “greedy,” best-first, strategy for choosing the support of new tokens. The resulting image description is rich and redundant in that a given segment of image contour may be described by multiple tokens at different scales, and by more than one token at any given scale. This property facilit’ates selection and characterization of portions of the image based on local CURVE-ELEMENT attributes