Hierarchical waveform matching: a new feature-based stereo technique

A feature-based stereo matching system that is based on an algorithm for one-dimensional waveform matching is described. It is intended for use in automated cartography, to generate an accurate three-dimensional model of man-made structures and natural terrain. Each epipolar line in the stereo pair is represented as a one-dimensional intensity waveform. The waveform is described as a collection of features, such as peaks and valleys, and represented across a set of hierarchical levels, computed by approximation from the original waveform. These features are matched using an evaluation function that factors similarity of waveform shape, intensity, and symbolic feature description. Waveform matches at coarse resolution are used to constrain matches at finer levels. Intra/inter-scanline corrections are applied and the actual position of the stereo match is adjusted by using the gradient representation of the original waveform. Some representative results are presented for a complex urban scene