Image output device and test chart for the same

摘要

In an image output device a test chart 18 including tests charts 6 of each color is used, and a tone correction table is calculated. The test charts 6 are patterned in a checkered pattern, each including continuous areas 10 in which the tones increase in steps and reference areas 11 for comparison with the continuous areas 10 . The reference areas 11 are formed of white ground of paper in a highlight proof part 7 , a solid pattern with a maximum density in a shadow proof part 8 , and halftone dot-concentrated or line screens with a lower resolution than in the continuous areas in a middle proof part 9 . Tone correction values are calculated from characteristic values of the highlight, shadow and middle parts, obtained from visual data of the test chart 18.