On Improving the Accuracy of Line Extraction in Hough Space

This paper presents an accurate line extraction technique — the Hierarchical Peak Compaction Hough Transform (HPCHT). Vote scattering in the parameter space is a problem when the Hough transform is used for line extraction. This paper investigates the effects of image size and edge data errors on the severity of vote scattering. The HPCHT uses the Hough procedure on small subimages initially, and a recursive Hough merging scheme on the extracted line segments afterwards. A bound on vote scattering has been derived which guides the image subdivision and the adaptive quantization of the parameter space. As a result, an accurate Hough transform of low ρ-scattering and high θ-precision has been achieved. The HPCHT is suitable for fast parallel implementation on pyramid computers.