| 摘要 |
PROBLEM TO BE SOLVED: To reduce the deterioration of the quality of an output image by connecting an image merging device with each buffer so as to merge each image into one output image after the filtering of a black text image, white text image, and background image stored in each buffer. SOLUTION: Background image information filtered by a low pass filter 72 is stored in a result image buffer 74. Black text image information and white text image information filtered by S-shaped filters 82 and 90 is respectively stored in result image buffers 84 and 92. The image information of the three result image buffers 74, 84, and 92 is combined by an image merging device 96. The black text, white text, and background parts of the original images are individually filtered, and each frequency characteristics are held so that the deterioration of the quality of an image as a result to be projected, which is made visible by a system in a preceding technology, can be reduced. |
