| 摘要 |
<p>A method and apparatus in which image data are pre-processed before undergoing block-basis image compression to compensate at least partially for the artifact known as the blocky effect that would otherwise be apparent upon decoding of the compressed data. The input data (1) are pre-processed (23) by combining error-correction data therewith, before block-basis compression is performed thereon. Blocky effect errors introduced during block-basis compression of the pre-processed input data and subsequent decoding will cancel, at least partially, the error-correction data, thereby compensating, at least partially, for the blocky effect that would otherwise occur without pre-processing. The error-correction data can be generated by performing block-basis compression (30, 31) on input data, then, performing the inverse transform (32) on the quantized data to generate test data; and then, computing the difference (33) between the input and test data to generate the error-correction data.</p> |
