PICTURE SIGNAL PROCESSOR, PICTURE SIGNAL PROCESSING METHOD AND PICTURE SIGNAL DECODER

摘要

PURPOSE: To reduce quantization noise and to make a pseudo contour generated by the ability limit of the picture signals of 8 bits inconspicuous. CONSTITUTION: The input picture signals of 8 bits from an input terminal 101 are supplied to a 10-bit making circuit 102 which is a bit extension means, bit-extended to the input picture signals of 10 bits and sent to a control signal output means 120 and a conversion part 130. In the conversion part 130, the input picture signals are smoothed by a low-pass filter(LPF) 103 and 2 bits on the LSB(least significant bit) side of the low-pass filter output are extracted and added with the original input picture signals. The control signal output means 120 compares the low-pass filter output with the original input picture signals and controls the conversion part 130 so as to use the original input picture signals as they are when the input picture signals are provided with high frequency components.