Exploiting color for edge extraction and line segment stereo matching

This paper investigates into the added value of color information for edge extraction and straight edge segment matching between stereo views. For edge extraction in color images different methods proposed in the literature are evaluated and compared, paying special attention to significance and completeness of the obtained edge-map. To find related edge segment pairs in different views, we apply an odd-man-out scheme: starting with all geometrically possible pairs we first rule out pairs, for which the chromatic information provided by the regions flanking the edge segments is incompatible. To further restrict the number of pairs we compute a chromatic similarity measure based on cross-correlation in the color bands. Both steps result in a significant reduction of candidate pairs, yet no correct pairs get lost. A main application of our technique is for automatic 3D building reconstruction from high resolution aerial images.