Incremental hough transform: A new method for circle detection

Abstract

The circle Hough transform (CHT) is a fundamental issue in image processing applications of industrial parts or tools. Because of its drawbacks, various modifications have been suggested to increase its performance. Most of them have met the problem of implicit evaluation of trigonometric functions that makes the implementation difficult. The CORDIC algorithm is used to simplify the trigonometric calculations when the basic CHT algorithm is implemented into a digital device such as FPGA. Although, this solution require computation time and device resources consumption for the CORDIC IP implementation. This paper presents a modified CHT method, called Incremental circle Hough transform (ICHT), suitable for hardware implementation. This method is mainly used to get around the implementation of CORDIC IP. This paper provides also the errors analysis of the proposed method against the basic CHT method to illustrate that it can replace the basic CHT method for small values of the resolution ε of the angle θ.