A modified valley-emphasis method for automatic thresholding

Otsu method is a commonly used technique for image thresholding selection, which can provide satisfactory results for thresholding an image with a histogram of clear bimodal distribution. This method, however, fails if the histogram is unimodal or close to unimodal. Ng (Ng, H.F., 2006. Automatic thresholding for defect detection. Pattern Recognition Lett. 27 1644-1649) proposed a modified method, called as valley-emphasis method, which weighs the objective function of the Otsu method with the valley point of the histogram for defect detection. In this paper, a revised valley-emphasis thresholding method is presented using the neighborhood information of the valley point. Experiment results show that the proposed method has the proper segmentation results in defect detection and provides better segmentation results than that of valley-emphasis method and Otsu method.

[1]  N. Otsu.  A threshold selection method from gray level histograms , 1979 .

[2]  Hui-Fuang Ng.  Automatic thresholding for defect detection , 2006, Pattern Recognit. Lett..

[3]  Josef Kittler,et al.  On threshold selection using clustering criteria , 1985, IEEE Transactions on Systems, Man, and Cybernetics.

[4]  Fujiki Morii.  An image thresholding method using a minimum weighted squared-distortion criterion , 1995, Pattern Recognit..

[5]  P.K Sahoo,et al.  A survey of thresholding techniques , 1988, Comput. Vis. Graph. Image Process..

[6]  Nabih N. Abdelmalek,et al.  Maximum likelihood thresholding based on population mixture models , 1992, Pattern Recognit..

[7]  Qingmao Hu,et al.  On minimum variance thresholding , 2006, Pattern Recognit. Lett..