| 摘要 |
PROBLEM TO BE SOLVED: To obtain a uniform image over an entire image area by correcting image data per one page on the basis of two dimensional characteristic data per one page to correct an uneven image depending on a difference from the sensitivity in an axial direction and a circumferential direction of a photoreceptor. SOLUTION: A scanner 4 of an image processing device 12 reads each test image reflecting a characteristic of an output device 1 obtained from an original image whose entire image area has a uniform density of 10, 20, and 50% that is outputted from the output device 1 and stores density data of each test image to a page buffer, two dimensional discrete wavelet transformation is applied to the data, a correction value of a low pass component is obtained by using correction data at an input level with density of 10, 20 and 50% to obtain uniform density with respect to image data with a density separated for each prescribed area, a high pass component is corrected and a low pass component is synthesized. Thus, even on the occurrence of uneven density caused by various factors of an output of the image output device 1, an image processing unit 12 obtains an image output with a uniform density over the entire image area in a breadthwise direction and a lengthwise direction. |
