| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an image formation apparatus which makes a pseudo outline not to be conspicuous in the border of a standard concentration pattern and a reference concentration pattern, and can accurately determine a shade by the observation of both patterns. <P>SOLUTION: A screen treatment part 217 has a low line-number line screen and a high line-number line screen which is different from the low line-number line screen in angle and line number. Standard concentration pattern data are screen-processed by the low line-number line screen, and the reference-tone pattern data are screen-processes by the high line-number line screen, respectively, in each shade contrast pattern data of a tone correction chart data generated by a tone correction chart generation part 215. A printing part 22 prints and outputs a tone correction chart wherein a standard concentration pattern and a reference concentration pattern are connected at a relative angle so that the total of the screen line number is maximum in the border of both the patterns in each shade contrast pattern based on the tone correction chart data after screen processing. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
