| 摘要 |
PURPOSE:To reduce influences exerted upon the output of noise when noise is loaded on input data by executing mask processing correction while considering plural adjacent picture element values for each picture element in input multilevel image data. CONSTITUTION:An average picture element density calculation part 5 calculates the average picture element density of a preceding line (the average of input multilevel image density correcting data 11) and corresponding to the level of density, a gradation correcting characteristic is corrected. When input multilevel image data 1 having a waveform (a) are directly inputted to a multilevel image transformation part 3, for example, there is the influence of noise at a high peak value, and noise (c) is remained at that part. In this case, however, the mask correction processing is executed to obtain the multilevel image correcting data 11 having a waveform (d) and afterwards, those data are inputted to the multilevel image transformation part 3 having a transforming characteristic (e) so as to remove the influence of noise at the high peak value. |
