| 摘要 |
PURPOSE:To select a light shade difference by binary-coded gradation processing by giving groups different rates of variation in high and low array of threshold levels for the binary-coded gradation processing, and performing the processing in accordance with the specification of gradation expression. CONSTITUTION:Comparison level data for the gradation processing of an analog picture signal are arrayed in two dimensions of bits in a main scanning direction and bits in a subordinate scanning direction Y, and groups which correspond to density indication signals are stored in an ROMDMD2. Each group of data has a different rate of variation in high and low array of threshold levels like 2a-2c, and the maximum value and minimum value are equalized in respective groups and set to four four-by-four matrix areas of each group 4c. Address data from a picture-element address specifying circuit ACC and an address switching circuit DMD are used to read comparison level data, which correspond to density specification signals 1-3, from the DMD2, and they are processed by A/D conversion and compared with the analog picture signal to perform binary-coding processing with a light and shade difference which corresponds to an original. |
