Abstract: A method of encoding and decoding a sequence of frames uses 3-D subband decomposition involving temporal filtering. Under certain conditions, for at least one pixel, the value of said pixel is approximated using one or more pixel values in the same frame.

Abstract: A method of representing a group of images comprises determining the values of one or more dominant colors for the group of images and deriving a dominant color representation expressing the group of images in terms of one or more of said dominant color values.

Abstract: A method of representing a group of images comprises determining the values of one or more dominant colours for the group of images and deriving a dominant colour representation expressing the group of images in terms of one or more of said dominant colour values.

Abstract: A method of representing a group of images comprises determining the values of one or more dominant colors for the group of images and deriving a dominant color representation expressing the group of images in terms of one or more of said dominant color values.

Abstract: A method of representing a group of images comprises determining the values of one or more dominant colors for the group of images and deriving a dominant color representation expressing the group of images in terms of one or more of said dominant color values.

Abstract: A method of representing a group of images comprises determining the values of one or more dominant colors for the group of images and deriving a dominant color representation expressing the group of images in terms of one or more of said dominant color values.

Abstract: A method of representing a colour image comprises selecting a region of the image, selecting one or more colours as representative colours for the region and, for a region having two or more representative colours, calculating for each representative colour at least two parameters related to the colour distribution in relation to the respective representative colour and using said parameters to derive descriptors for the image region.

Abstract: A technique and system of representing a group of images, the technique includes determining the values of one or more dominant colors for the group of images and deriving a dominant color representation expressing the group of images in terms of one or more of said dominant color values. The inventive technique and system can be applied to any group of images, or image regions, including regions within image.

Abstract: An improved MPEG adaptive reference fine granularity scalability encoder and decoder is described. The parameters ? and ? used to weight difference data during the generation of a prediction error signal in an enhancement layer are modified in dependence upon the magnitude of the values in the difference data.

Abstract: A method of deriving replacement block information, such as a replacement motion vector, for a lost or damaged image block in scalable video coding comprises combining information about neighbouring block information in at least the current layer and the corresponding and/or neighbouring blocks in at least one other layer, to derive said replacement block information.

Abstract: A method of representing an image or sequence of images using a depth map comprises transforming an n-bit depth map representation into an m-bit depth map representation, where m<n, using a non-linear transformation.

Abstract: A method of representing motion of an object appearing in a sequence of images comprises deriving for each image a set of representative points representing the location of the object, deriving an approximate function representing the trajectory of a representative point in two or more of said sequence of images, and calculating an error value for said approximate function for the representative point for an image, characterised in that the error value is based on the difference between the area of the object as represented by the representative point and the area of the object with the representative point replaced by the respective approximate function value.

Abstract: A method of representing a group of images comprises determining the values of one or more dominant colours for the group of images and deriving a dominant colour representation expressing the group of images in terms of one or more of said dominant colour values.

Abstract: A method of representing a group of images comprises determining the values of one or more dominant colours for the group of images and deriving a dominant colour representation expressing the group of images in terms of one or more of said dominant colour values.

Abstract: A method of representing a group of images comprises determining the values of one or more dominant colours for the group of images and deriving a dominant colour representation expressing the group of images in terms of one or more of said dominant colour values.

Abstract: A method of representing a group of images comprises determining the values of one or more dominant colours for the group of images and deriving a dominant colour representation expressing the group of images in terms of one or more of said dominant colour values.

Abstract: A method of representing a group of images comprises determining the values of one or more dominant colours for the group of images and deriving a dominant colour representation expressing the group of images in terms of one or more of said dominant colour values.

Abstract: A method of encoding a sequence of frames using 3-D decomposition, the method comprising dividing the frames into blocks and coding the blocks, wherein coding a current block comprises evaluating at least one neighbouring block in the same frame and making a determination about whether to code data in the region of the current block corresponding to a neighbouring block depending on the evaluation of said at least one neighbouring block.

Abstract: A method of encoding a sequence of frames for transmission comprises encoding a sequence of frames under different conditions to produce a plurality of encoded bit streams each representing the sequence of frames, for transmission at different bit rates, and storing each of the encoded bit streams in a respective buffer, and outputting a bit stream from a buffer for transmission, and the method further comprises switching between buffers to change the bit rate of the data for transmission, wherein at least one frame to be stored in one buffer is encoded with reference to a frame stored in another buffer.

Abstract: A method of representing a colour image comprises selecting a region of the image, selecting one or more colours as representative colours for the region and, for a region having two or more representative colours, calculating for each representative colour at least two parameters related to the colour distribution in relation to the respective representative colour and using said parameters to derive descriptors for the image region.