Automatic threshold estimation for gradient image segmentation
Tianxu Zhang, Xinsai Wang, Yuehuan Wang · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2001
The gradient histogram has unimodality. It has been found from the statistics of the gradient histogram for large numbers of images that the gradient histograms of the object and background can be fitted with the X2 distribution density function of different degrees of freedom. A method of automatic estimation of the threshold of gradient image segmentation is presented and proved.