| 摘要 |
PURPOSE:To provide the copy machine with area editing function which can automatically set a judgement level without dispersion in the case of judging the presence/absence of a marker attached to an original. CONSTITUTION:In a step ST1, the white part of a reference original coloring the first half in white and the latter half in red concerning an original scanning direction, for example, is read and in a step ST2, an output from a CCD image sensor is stored in a memory after A/D conversion. In a step ST3, the image sensor reads the red part of the reference original. In a step ST4, respective color outputs from the CCD image sensor are stored in the memory after A/D conversion. In a step ST5, after the reference original is completely read, a CPU calculates the average values of digital signals corresponding to analog signal outputs from the image sensor concerning the white and red parts of the reference original. In steps ST6, ST7 and ST8, the CPU respectively calculates a gain A, upper limit luminance level VH and lower limit luminance level VL by using the average values calculated in the ST5, and these calculated values are stored in the memory in a step ST9. |
