IMAGE BINARIZATION THRESHOLD COMPUTING APPARATUS

This invention relates to an image binarization threshold computing apparatus comprising a window scanning means for setting a window of predetermined area over a multilevel image and scanning the same image, a first information generating means for generating a first data on brightness of the image within the window, a second information generating means for generating a second data on fitness of the image within the window with respect to a preset pattern, a third information generating means for generating a third data serving as a picture quality assessment criterion from the first and second data, and an optimal threshold computing means for calculating the optimal threshold value providing the best picture quality according to the third data.