| 摘要 |
<p>PURPOSE:To provide a picture signal decoder for removing the mosquito noise of a color difference signal generated by decoding high-compressed picture data. CONSTITUTION:In a color difference signal changing part 1, a signal f(x) for which a DCT coefficient F(u) is IDCTed is obtained from the color difference signal Cb obtained by decoding the compression of the color difference signal (original signal) C of an input picture, an approximate signal f'(x) is found from the signal f(x) based on luminance signal picture element discrimination information 2 and the DCT coefficient F'(x) is found by DCTing the signal f'(x). Then, a color difference signal DCT coefficient 4, that is, the DCT coefficient F(u) and the DCT coefficient F'(x) are compared at a discrimination part 3, output is performed when the formula of prescribed conditions is realized and when it is not realized, the color difference signal changing part 1 is returned, the DCT coefficient F'(x) is found again and fluctuation part generated at a flat part of a source picture signal at the time of compression decoding is removed.</p> |
