CONNECTED EQUI-LENGTH LINE SEGMENTS FOR CURVE AND STRUCTURE MATCHING

Abstract

This paper deals with the problem of matching curves and structures extracted from 2D images that are subject to translation, rotation, scaling and other geometric transformations. We present in this paper a novel approach, Connected Equi-Length Line Segments (CELLS), for curve representation and matching. In our framework, a curve is represented by a number of connected equi-length line segments and a new matrix called Orientation Difference Matrix (ODM) is constructed for the curve, which reflects the distribution of the rest of the line segments with respect to the current one using orientation differences between them. The representation is invariant to rotation, scaling and translation. The problem of structure matching is also considered in this paper and is solved based on CELLS. The matching of structures is performed by (1) detecting tri-junctions and quad-junctions on the structures, (2) representing each arch using CELLS. A practical use of the proposed approach is demonstrated by registering a SAR image of a certain area to a map.