| 摘要 |
PURPOSE:To attain color processing at a high speed without provision of a circuit for each color by extracting a black component signal based on received color sequential image data and rewriting a dummy signal based on the black component signal. CONSTITUTION:A minimum value detection circuit 15 calculates a minimum value of parallel image data to be black data. The black data from the minimum value detection circuit 15 are given to a UCR(under color reduction) table 16, the UCR table 16 decides a complement of the UCR quantity for each mode represented by a mode signal 6 and gives the result to an adder 17. A delay register 13 delays an output of the adder 12 by a required delay time so as to match phases of two inputs to the adder 17 with each other. Then the adder 17 conducts the UCR processing for color sequential data and replaces black dummy data in the color sequential data with black data calculated by the minimum value detection circuit 15. Thus, the data are corrected in matching with the gradation characteristic of a printer. |
