Patent ID: 7149370

Claim:
A method of conveying image data of an image having an initial quality in a codestream between a source and a target in a wireless communications network, wherein the image is composed of a plurality of image tiles, each image tile comprising a plurality of tile sub-components organizable in a parametric order, and wherein the target has a memory means to store at least a portion of the image conveyed in the codestream, the image stored in the target including tile sub-components in one or more image tiles, said method comprising: arranging at least part of the memory means into a plurality of memory locations in cache so as to allow the image data of the tile sub-components in each of said one or more tiles to be stored in a different location of said memory means according to the parametric order; selecting in the target a subimage part of said image for display at an increased quality level greater than said initial quality of the image stored in the memory means, providing a message to the source from the target indicative of an increased amount of tile sub-components of said one or more image tiles needed from the source in order to achieve the increased quality level of the selected subimage part of said image so as to allow the source to convey further image data of the image in the codestream including the increased amount of tile sub-components in response to the message; specifying in the target a further subimage part of said image for display at said increased quality level, wherein said specified further subimage part is at least partially different from the selected subimage part, providing a further message to the source from the target indicative of a further amount of tile sub-components of one or more of said tiles needed from the source in order to achieve said increased quality of the specified further subimage part so as to allow the source to convey additional image data of the image in the codestream including the further amount of tile sub-components in response to the further message; and deleting the image data of said at least portion of the non-selected part from one or more locations of said memory means, wherein said at least portion of the non-selected part includes image data of tile sub-components in some of said one or more image tiles, and wherein said deleting is partially based on the distance between the tiles in said at least portion of the non-selected part and the further subimage part.