| 摘要 |
PROBLEM TO BE SOLVED: To provide the simple and proper method that is used for applications where image quality of a signal that is digitally compressed in comparison with image quality of the signal before compression. SOLUTION: The image quality is estimated at first by introducing a difference signal 35 representing a difference between a video signal of a version 31 receiving distortion and a video signal of a version 30 without distortion. A masking signal is obtained by filtering (50) the version 30 of the video signal without distortion and is used to obtain an output scale of the image quality difference by masking the difference signal. A masking signal 41 is obtained by filtering the version 30 of the video signal without distortion through the high pass edge detection filter 50. If possible, a 2nd image quality difference scale is preferably obtained with a circuit 38 that detects block distortion on block borders and adding the version of the video signal receiving distortion and the version of the video signal without distortion. An output from the block distortion circuit 38 is masked by the masking signal. |
