Thresholding is an important form of image segmentation and is used in the
processing of images for many applications. One of the criteria to select a
suitable threshold is the maximization of the two-dimensional (2-D) entrop
ies based on the 2-D (gray-level/local average gray-level) histogram. The r
ationale of this approach is introduced. In order to reduce the computation
time of entropy function, a fast recurring algorithm for 2-D entropic thre
sholding method is presented. The experimental results show that the proces
sing time to obtain the threshold vector from 2-D histogram is reduced from
30 to 0.15 s. (C) 1999 Pattern Recognition Society. Published by Elsevier
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