| 摘要 |
PROBLEM TO BE SOLVED: To monitor deterioration in original image quality in a process of transmission or processing without being influenced by the difference between bands even if video images have bands different from each other. SOLUTION: A video image (e.g. digital signal having a band of 6 MHz) is distributed to a set-top box (STB) 14 via a compression coder 11, a distribution server 12, and a network 13. A low-pass filter 151 of an image quality monitoring apparatus 15 omits a high-pass component of a digital signal to be inputted, and inputs a luminance signal band-limited to 4 MHz into a PSNR calculator 153. A Y/C separator 152 separates a luminance signal and a color difference signal from an analog composite signal of an NTSC system to be outputted from the set-top box 14. The separated luminance signal Y has a band of 4 MHz. The PSNR calculator 153 uses a luminance signal from the low-band filter 151 and a luminance signal from the Y/C separator 152 as an input, and calculates PSNR between both. COPYRIGHT: (C)2007,JPO&INPIT
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