Method and device for adaptive noise measurement of a video signal

摘要

The present invention relates to method of adaptive noise measurement of a video signal comprising a sequence of images. The proposed method comprises the steps of searching one or more spatially uniform areas within a current image, determining a spatial uniformity value of said one or more spatially uniform areas and combining said spatial uniformity values to obtain a spatial noise value representing a first measure for the amount of noise in said current image, detecting motion by comparing the current image with one or more preceding images and/or one or more succeeding images of said sequence of images by use of a motion threshold to obtain one or more motion maps indicating the amount of motion between the current image and the respective preceding or succeeding image, searching one or more static areas within said one or more motion maps, determining a temporal uniformity value for said one or more static areas by comparing image values at positions in said one or more preceding images and/or said one or more succeeding images, at which a low amount or no motion is indicated in the respective one or more motion maps, said temporal uniformity value representing a measure for the amount of noise at said positions in said current image, and combining said obtained temporal uniformity values to obtain a combined noise value representing a second measure for the amount of noise in said current image.

主权项

1. A method of adaptive noise measurement of an input video signal, said method comprising:
receiving the input video signal, the input video signal including a current image, one or more preceding images and one or more succeeding images; searching for one or more spatially uniform areas within the current image; determining a spatial uniformity value of said one or more spatially uniform areas and combining said spatial uniformity values to obtain a spatial noise value that represents a first measure for the amount of noise in said current image; detecting motion by comparing the current image with the one or more preceding images and the one or more succeeding images by using the spatial noise value as a motion threshold; obtaining one or more motion maps from said detected motion, said one or more motion maps indicating the amount of motion between the current image and the respective one or more preceding images or the one or more succeeding images; searching for one or more static areas within said one or more motion maps; determining, by circuitry, a temporal uniformity value for each of said one or more static areas in said one or more motion maps by comparing image values, at positions in said one or more preceding images and said one or more succeeding images, at which a low amount of motion or no motion is indicated in the respective one or more motion maps, and said temporal uniformity value representing a measure for the amount of noise at said positions in said current image; and combining said determined temporal uniformity values to obtain a combined noise value representing a second measure for the amount of noise in said current image.