CODER

摘要

PURPOSE:To reduce quantity of data almost without deteriorating picture quality by providing a dynamic range calculator and a compression rate controller to the coder so as to vary the compression rate depending on the dynamic range. CONSTITUTION:A dynamic range 5 of an input signal 1 is calculated by a dynamic range calculator 4 and the dynamic range 5 is calculated by the same function block as that for orthogonal transformation. When the dynamic range 5 is high, a compression rate controller 8 controls a compression parameter 9 so that the quantity of data is reduced with an increased compression rate and a coder 10 encodes an orthogonal transforming signal 3 with the compression parameter 9. Thus, the quantity of data is reduced almost without deteriorating the picture quality.