The Cascaded Hough Transform as Support for Grouping and Finding Vanishing Points and Lines

In the companion paper 7] a grouping strategy with a rm geometrical underpinning and without the problem of combinatorics is proposed. It is based on the exploitation of structures that remain xed under the transformations that relate corresponding contour segments in regular patterns. In this paper we present a solution for the complementary task of extracting these xed structures in an eecient and non-combinatorial way, based on the iterated application of the Hough transform. Apart from grouping, this`Cascaded Hough Transform' or CHT for short can also be used for the detection of straight lines, vanishing points and vanishing lines.