Picture quality monitoring apparatus
AssigneeKddi Corporation
InventorsRyoichi Kawada, Osamu Sugimoto, Atsushi Koike
Life of this patent
Estimating the term…
Abstract
Picture having a band of 6 MHz is distributed to the set-top box (STB) 14 via the compression encoder 11, the distribution server 12, and the network 13. The low-pass filter 151 in the picture quality monitoring apparatus 15 removes high-frequency components of an inputted digital signal and inputs luminance signal, the band of which is limited to 4 MHz, into the PSNR calculator 153. The Y/C separator 152 separates a luminance signal from NTSC analog composite signal, which are sent out from the set-top box 14. The separated luminance signal has a band of 4 MHz. The PSNR calculator 153 calculates PSNR between the luminance signal from the low-pass filter 151 and the luminance signal from the Y/C separator 152.
Claims14
A picture quality monitoring apparatus for monitoring a picture quality degradation between an original picture and a processed picture whose band is limited by processing the original, comprising:
- a first horizontal low-pass filter, applied to at least the original picture, for matching the bands of the original picture and the processed picture;
- and
- a comparing means for comparing the picture qualities of the original picture and the processed picture, the bands of which are matched by the first horizontal low-pass filter,
- wherein the original picture is of a digital signal and the processed picture is of an analog signal.
A picture quality monitoring apparatus for monitoring a picture quality degradation between pictures at two or more points on a transmission link that includes a plurality of transmission apparatus in tandem, comprising:
- picture extracting means for extracting pictures at two or more points on a transmission link;
- a first horizontal low-pass filter, applied to at least one picture of the pictures, for matching the bands of the respective pictures extracted by the picture extracting means;
- characteristic extracting means for extracting picture quality characteristic amounts of the respective pictures whose bands are matched by the first horizontal low-pass filter;
- and
- transmitting means for transmitting the picture quality characteristic amounts extracted by the characteristic amount extracting means to a central monitoring room;
- wherein the respective picture quality characteristic amounts are compared with each other in the central monitoring room, and the picture quality degradation of the transmitted picture is monitored, and
- wherein at least one picture to which the first horizontal low-pass filter is applied is of a digital signal and the other picture is of an analog signal.
Dependencies are inferred from the claim text.