Abstract: The present invention relates to an apparatus and method for normalization of an image signal, particularly for use in perceptual video and still image quality measurement when the quality measurement is achieved by making a comparison between a reference signal and a decoded signal. The invention provides a method for normalizing a decoded image signal in relation to a reference image signal to generate a normalized image signal comprising the steps of: generating a non-linear transformation vector in dependence upon at least one component of the decoded image signal and at least one component of the reference image signal; and applying said non-linear transformation vector to at least one component of the decoded image signal to generate a normalized image signal. Methods and apparatus for perceptual video and still image quality measurement using said method are also provided.

Abstract: The present invention relates to an apparatus and method for processing images, in particular for determining the degree of blockiness in coded images.

Abstract: This invention relates to alignment of signals, particularly for use in a quality assessment system.

Abstract: This invention provides a parameter for use in assessing video quality based on temporal frame freezing for use in an apparatus and method for perceptual video quality measurement. The invention provides a method of generating a freeze frame parameter relating to the perceptual impact of frozen frames in a video signal comprising the steps of: identifying frozen frames; identifying a freeze event comprising a plurality of consecutive frozen frames, the freeze event having a duration in dependence upon the number of frozen frames in said sequence; defining a set of duration ranges; and generating a freeze frame parameter in dependence upon the number of freeze events having a duration falling within each duration range. Methods and apparatus for perceptual video quality measurement using the method are also provided.

Abstract: The present invention relates to an apparatus and method for processing images, in particular for determining the degree of blockiness in coded images. The invention comprises apparatus and methods for determining a degree of blockiness in a digital image comprising blocks each block comprising a plurality of rows and a plurality of columns of pixels each pixel having a value by performing the steps of: for each block determining an intra block measure in dependence upon the values of a set of pixels within said block; and determining said measure in dependence upon a plurality of said intra block measures corresponding to each block. Method and apparatus for generating a quality measure in dependence upon the measure of blockiness are also provided.

Abstract: This invention relates to alignment of signals, particularly for use in a quality assessment system.

Abstract: The present invention relates to an apparatus and method for processing images, in particular for determining the degree of blockiness in coded images. The invention comprises apparatus and methods for determining a degree of blockiness in a digital image comprising blocks each block comprising a plurality of rows and a plurality of columns of pixels each pixel having a value by performing the steps of: for each block determining an intra block measure in dependence upon the values of a set of pixels within said block; and determining said measure in dependence upon a plurality of said intra block measures corresponding to each block. Method and apparatus for generating a quality measure in dependence upon the measure of blockiness are also provided.

Abstract: This invention provides a parameter for use in assessing video quality based on temporal frame freezing for use in an apparatus and method for perceptual video quality measurement. The invention provides a method of generating a freeze frame parameter relating to the perceptual impact of frozen frames in a video signal comprising the steps of: identifying frozen frames; identifying a freeze event comprising a plurality of consecutive frozen frames, the freeze event having a duration in dependence upon the number of frozen frames in said sequence; defining a set of duration ranges; and generating a freeze frame parameter in dependence upon the number of freeze events having a duration falling within each duration range. Methods and apparatus for perceptual video quality measurement using the method are also provided.

Abstract: The present invention relates to an apparatus and method for processing images, in particular for determining the degree of blockiness in coded images.

Abstract: The present invention relates to an apparatus and method for normalisation of an image signal, particularly for use in perceptual video and still image quality measurement when the quality measurement is achieved by making a comparison between a reference signal and a decoded signal. The invention provides a method for normalising a decoded image signal in relation to a reference image signal to generate a normalised image signal comprising the steps of: generating a non-linear transformation vector in dependence upon at least one component of the decoded image signal and at least one component of the reference image signal; and applying said non-linear transformation vector to at least one component of the decoded image signal to generate a normalised image signal. Methods and apparatus for perceptual video and still image quality measurement using said method are also provided.