On minimum error thresholding and its implementations

Ahstract: In this paper we discuss the thresholding methods [1] due to Kittler and Illingworth. Two methods arc suggested in [1]. namely, 1) minimizing a criterion function and 2) iterative search of the minimum error threshold. We have tested the two methods. The first one is found to be robust even in the case of weak bimodality in the histogram. The second one is faster than the first, but a good initial threshold must be provided. We have proposed to use the method of Ridler [3] and Trussel [4] to select the initial threshold. Experimental results show that if the initial threshold is selected this way the second method is as robust as, the first one, but the speed of the whole procedure is much faster.