| 摘要 |
A method for intraframe image compression of an image is combined with a method for reducing memory requirements for an interframe image compression. The intraframe image compression includes (a) dividing the image into blocks; (b) selecting a block according to a predetermined sequence; and (c) processing each selected block by: (1) identifying a reference block from previously processed blocks in the image; and (2) using the reference block, compressing the selected block. The selected block may be compressed by compressing a difference between the selected block and the reference block, where the difference may be offset by a predetermined value. The difference is compressed after determining that an activity metric of the difference block exceeds a corresponding activity metric of the selected block. The activity metric is calculated for a block by summing a difference between each pixel value within the block and an average of pixel values within the block. The reference block is identified by: (a) for each of the previously processed blocks, calculating a sum of the absolute difference between that block and the selected block; and (b) selecting as the reference block the previously processed block corresponding to the least of the calculated sums.
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