Patent ID: 7496139

Claim:
A bit reduction apparatus comprising: a picture quality correction circuit for correcting picture quality of input video signal and outputting a corrected picture; a first bit reduction unit for producing a first reduced bit picture by reducing a number of bits of the corrected picture outputted by picture quality correction circuit, and outputting a first reduced bit picture; a second bit reduction unit for producing a second reduced bit picture by reducing the number of bits of the corrected picture outputted by the picture quality correction circuit, and outputting a second reduced bit picture; a discriminating circuit for generating a discrimination signal at least as one factor for judging the detection result of a synchronizing signal of the input video signal; and a first selector controlled by the discrimination signal selecting between one of the first reduced bit picture output by the first bit reduction unit and the second reduced bit picture output by the second bit reduction unit, wherein the first bit reduction unit includes a first noise shaping circuit for shaping noise of the corrected picture of the picture quality correction circuit and reducing the number of bits of the corrected picture, and wherein the bit reduction apparatus outputs an output video signal that has fewer bits than the input video signal.