| 摘要 |
PURPOSE:To obtain a picture processor by which the deterioration of a picture quality at the edge neighborhood of a picture can be reduced at the time of expanding the compressed picture. CONSTITUTION:The picture data are orthogonally transformed by a DCT circuit 102, an orthogonal transformation factor F (i) is successively supplied to an AC power value detecting part 104, and a quantizer Q106 by a zigzag scan circuit 103. An appropriate quantization step Q (i) and an add value A (i) by which the deterioration of the picture quality can not be generated, are supplied from a Q table 105 to a Q 106, from the power value of the orthogonal transformation factor F (i) detected by the AC power value detecting circuit 104, and the address (i) of the orthogonal transformation factor F (i). The orthogonal transformation factor F (i) is quantized by the Q 106 by using a quantization threshold value decided by the quantization step Q (i) and the add value A (i). Then, the quantized orthogonal transformation factor F (i) is compressed by an encoding circuit 107. |
