Image forming apparatus that corrects input gray level-output gray level characteristic data such that output gray levels gradually increase with higher input gray levels near a boundary

摘要

In an image forming apparatus according to the present invention, characteristic correcting data for correcting input gray level-output gray level characteristics for each of a plurality of steps into which input gray levels are divided is inputted by an inputting device. At the time of image formation processing, input gray level-output gray level characteristic data are corrected on the basis of the characteristic correcting data inputted by the inputting device. Further, when there occurs at the boundary between adjacent steps such a reversal phenomenon that an output gray level in the step having relatively low input gray levels is higher than an output gray level in the step having relatively high input gray levels in input gray level-output gray level characteristic data obtained by correction using a correcting device, the input gray level-output gray level characteristic data are so corrected that output gray levels gradually increase with higher input gray levels in the vicinity of the boundary.