THRESHOLDING METHODS CONSIDERING THE QUANTIZATION-ERROR OF AN IMAGE

Thresholding techniques are fundamental for region segmentation of a g ray level image. It is often realistic to assume that gray pixel level s are subject to a mixture of normal distributions. This paper points out problems caused by the underestimation of variances from a frequen cy distribution and solves the problems by transforming a frequency di stribution into a piecewise-continuous distribution based on the maxim um entropy criterion. This transformation improves conventional thresh olding techniques. Experimental results showed the effectiveness of th e transformation.