PROBLEM TO BE SOLVED: To provide an image compressing apparatus and an image compressing method capable of efficiently performing compression process at a high compression rate while degradation in image quality is reduced by using lossy compression process and lossless compression process in combination.SOLUTION: When compressing continuous tone bit map image data, an image compression section 4 segments the continuous tone bit map image data into; bit map image data for lossy compression; index image data for lossless compression; and bit map image data for lossless compression, on the basis of pixel identification information data. The lossy compression section 45 performs lossy compression process using the JPEG method for the bit map image data for lossy compression, and a first lossless compression section 46 performs lossless compression process using the JBIG method for the index image data for lossless compression. A second lossless compression section 47 performs lossless compression process using the JPEG-LS method for the bit map image data for lossless compression.
展开▼
