| 摘要 |
PURPOSE:To quickly and simply apply color correction to an original having all density area by excluding the minimum and the maximum density below a threshold level from a toner density distribution comparison means and providing a correcting means for each original having all density areas based on the obtained minimum and maximum density value. CONSTITUTION:A histogram generator 29a of a CPU29 calculates a frequency of picture elements having each toner density with respect to a picture based on each toner density of each picture element obtained by processing data read from an original 7 stored in a RAM30 to generate a histogram as a toner density distribution comparison means from each toner. Then the maximum density and the minimum density in each toner are obtained from the histogram. Density data corresponding to picture elements below a threshold level are excluded among values corresponding to the minimum and maximum values of the toner density on the histogram by providing the threshold level to the frequency of the picture elements of the histogram with respect to the picture to decide the maximum and minimum density of each toner in the original picture. |
