| 摘要 |
A fast, raster-based, enhanced, data compression technique (FIG. 1) for the printing of compound documents, including pre-processing images in an original page description form of the data before the page data is rasterized and compressed greatly improves compressibility. Higher throughput and compression ratios are enabled by taking advantage of image pixel-replication resolution enhancement (FIGS. 2, 2A, 2B, 3A and 3B) before rasterization actually occurs. Unscaled image data is filtered before it is rasterized to the final printing resolution. The filtering specifically enables a separate near loss-less compression algorithm (FIGS. 4, 4A, 4B and 5) to operate on a rasterized page description with high compression ratios. A data compression technique enables a system to compress compound document using a relatively fast and simple algorithm with near loss-less print quality. <IMAGE> |
