It is used in the proposed method to improve the efficiency of searching the optimal thresholds. The basic concept is to first segment the original gray image to three gray level images, then treat the dark part, the medium part and the bright part as three new input images , , and with the same gray information. Finally, choose one or more images from , , and and perform the above segmentation process recursively until the pre-specified number of segments is reached.
Published in Chapter:
A Hierarchical Multilevel Image Thresholding Method Based on the Maximum Fuzzy Entropy Principle
Pearl P. Guan (City University of Hong Kong, Hong Kong) and Hong Yan (City University of Hong Kong, Hong Kong & University of Sydney, Australia)
Copyright: © 2013
|Pages: 32
DOI: 10.4018/978-1-4666-2518-1.ch010
Abstract
Image thresholding and edge detection are crucial in image processing and understanding. In this chapter, the authors propose a hierarchical multilevel image thresholding method for edge information extraction based on the maximum fuzzy entropy principle. In order to realize multilevel thresholding, a tree structure is used to express the histogram of an image. In each level of the tree structure, the image is segmented by three-level thresholding based on the maximum fuzzy entropy principle. In theory, the histogram hierarchy can be combined arbitrarily with multilevel thresholding. The proposed method is proven by experimentation to retain more edge information than existing methods employing several grayscale images. Furthermore, the authors extend the multilevel thresholding algorithm for color images in the application of content-based image retrieval, combining with edge direction histograms. Compared to using the original images, experimental results show that the thresholding images outperform in achieving higher average precision and recall.