QUANTIZING METHOD FOR PICTURE SIGNAL

摘要

PURPOSE:To increase coincidence rate of forecasting by using a forecasted value as the quantized picture-element signal of a picture element obtained by a scan if the difference between an actual value and the forecasted value is less than a correction limit value when luminance information on said picture element is quantized. CONSTITUTION:During the processing of picture elements, the composite picture- element luminance signal of the luminance signal of a picture element quantized by a quantizing device and a correction signal which is the sum of correction element signals is compared with a forecasted luminance signal from a forecasting device 4 by a comparing and correcting device 3. When the difference between the both is less than a correction limit value, the forecasted brightness signal is used as the picture-element signal of the picture element. When the difference is greater than said limit value, a quantized value close to the picture- element luminance signal of the picture element is used as the picture-element signal. Further, an error luminance signal which is the difference between the picture-element signal and picture-element luminance signal is regarded as a correction element signal of the picture element to be processed after picture elements adjoining to the picture element.