ADAPTIVE THRESHOLD DEVICE FOR IMAGE PICTURE ELEMENTS AND ADAPTIVELY THRESHOLDING METHOD

摘要

An adaptive thresholder of the fractional average context type for processing image pixels in which an offset potential, which is used in conjunction with the image potentials of the nearest neighbor pixels to provide an updated threshold potential, is obtained on a pixel by pixel basis as a function of the pixel white peak and black valley potentials. The white peak and black valley potentials are compared with the image potential of each pixel being processed and with predetermined minimum white and maximum black potentials to provide updated white peak and black valley potentials for use in updating the offset potential during processing of each pixel.