| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an image encoder capable of quickly and highly efficiently compressing a general business document image including gradation, characters, a table, a natural image, etc. SOLUTION: The image encoder is provided with a block division means 1903 for dividing multi-valued image data into blocks each of which consists of pixels, a scanning conversion means 1904 for converting a scanning pattern in each block, a run reconstitution means 1907 for combining a run of short length to peripheral runs and determining the color of the combined run by using a pixel value in the combined run, a run length calculation means 1909 for calculating the length of a run expressing the continuity of pixels of the same color in a data group to which scanning conversion and run reconstitution are applied, a color storing buffer 1910 for storing the colors of pixels appearing before the run, a color information determination means 1911 for determining the color information of the run on the basis of the color information of the buffer 1910, and an entropy encoding means 1912 for executing the entropy encoding of the run length and the color information.</p> |
