Patent ID: 6101290
Filing Date: 2000-08-08
Classification: G06T

Abstract:
A method of caching source image data to be transformed to transformed image data for a 90 or 270 degree rotation, in accordance with transform coefficients by a multiprocessor system having a cache memory with a predetermined size, comprising the steps of:providing a destination block and said cache memory with a predetermined size;calculating the destination block width and destination block height of said destination block, said destination block to contain said transformed image data in destination space in said destination block, said step of calculating being performed by expressing said destination block width and said destination block height in terms of the width of the source image data, said transform coefficients, and said cache memory with predetermined size, thereby obtaining two equations, and by solving said two equations;calculating said bounding box width and said bounding box height as functions of said destination block width, said destination block height, and said transform coefficients; andtransferring said source image data contained within said bounding box to said cache memory;calculating a transfer cycles value representing the number of transfer cycles required to transfer said data in said bounding box and being a function of said destination block width, said destination block height, said bounding box width, and said bounding box height;repeating all of said steps prior to said transferring step to determine a minimum transfer cycles value, thereby determining optimum values of said bounding box width and said bounding box height.