| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an image compressing method, an image compressing apparatus, an image forming apparatus, a computer program and a recording medium in which a file size attained after compression is sufficiently small while suppressing large degradation of image quality attained after the compression. <P>SOLUTION: When N kinds of foreground identifiers for identifying color information of a foreground of a color image is to be reduced to M smaller than N, foreground identifiers corresponding to similar chromatic colors are merged and foreground identifiers corresponding to similar achromatic colors are merged but a foreground identifier corresponding to a chromatic color and a foreground identifier corresponding to an achromatic color are not merged by an index image generating unit 32. Thus, image quality degradation derived from color change from an achromatic color to a chromatic color or vice versa may be suppressed. After that, on the basis of a foreground layer including the M kinds of foreground identifiers, M binary images respectively corresponding to the M kinds of foreground identifiers are generated by a binary image generating unit 34, each of the binary images is subjected to lossless compression and a background layer is subjected to lossy compression by an image compressing unit 35. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
