| 摘要 |
<P>PROBLEM TO BE SOLVED: To efficiently determine whether each block is a black-and-white block, a gray block and a chromatic block using a histogram. <P>SOLUTION: In an image processing device, an image represented in a YCbCr color space is divided into plural blocks to create a histogram of a value of Y-component of pixels constituting the block for each block. A most frequent value of the Y-component and a ratio of the most frequent value are found for each block, and whether the block is a monochrome block or a multicolor block is determined based on the ratio of the most frequent value. Whether the monochrome block is an achromatic block or a chromatic block is determined, and the achromatic block is determined as a black-and-white block when the most frequent value of the Y-component is not more than a first threshold or not less than a second threshold larger than the first threshold, and otherwise is determined as a gray block. <P>COPYRIGHT: (C)2013,JPO&INPIT |
