Patent ID: 8400460
Filing Date: 2013-03-19
Classification: G06F,H04N

Abstract:
1. An image data processing method in which a cache memory is used, a predicted value is generated according to reference image data that is held in a reference image memory, and moving image data is coded and/or decoded with the aid of the predicted value, comprising: specifying an area of the reference image data on a screen by one-dimensional address data of the reference image memory, and requesting the reference image data that is used for generation of the predicted value from the cache memory; retrieving reference image data corresponding to the request from the reference image data that is stored in the cache memory, the retrieving including transforming the one-dimensional address data into two-dimensional address data indicative of a position of the reference image data on the screen by selecting a first number of bits of the one-dimensional address data as first two-dimensional address data and selecting a second, nonadjacent portion of the one-dimensional address data having a second number of bits as second two-dimensional address data, the retrieving varying the first number of bits and the second number of bits based on a vertical size and a horizontal size of the area; generating an index of the cache memory by concatenating the first two-dimensional address data with the second two-dimensional address data such that a last bit of the first two-dimensional address data is directly before a first bit of the second two-dimensional address data in the index; outputting the reference image data that is stored in the cache memory in response to the request when the corresponding reference image data is stored in the cache memory; and storing the corresponding reference image data that is stored in the reference image memory in the cache memory, and also outputting the corresponding reference image data in response to the request when the corresponding reference image data is not stored in the cache memory, wherein the reference image memory outputs the reference image data in a read unit of a plurality of pixels which are continuous in a horizontal direction or a vertical direction, and wherein the area is an area that is a plurality of the read units in the horizontal direction and the vertical direction, respectively.