Efficient Constitution of Look-up Tables for High-Speed Hough Transform

Abstract

The table look-up is a powerful method for high-speed execution of the Hough transform, and this paper describes how an efficient look-up table should be arranged. Investigating the constitution of the table from the viewpoint of size, number of execution steps, execution times, amount of error, etc reveals that the best way is to prepare a table based on the equationρ=r·sin (θ+φ), derived from p=x·cosθ+y·sinθ (which is the original equation of the Hough transform) A software experiment showed that the time of θ-ρ plane drawing is reduced 80-fold from that using the original Hough transform equation The proposed principle is implemented in experimental hardware in which the dimension of the plane in 512 (9bit) ×512, and only one ROM.The drawing time for one point on the θ-ρ plane is less than 100 ns.