| 摘要 |
PURPOSE:To obtain a binary circuit for a contrast image taking advantage of the first lattice point pixel and the second lattice point pixel of a contrast image by separating these pixels, performing binary processing of the pixels by separate methods and synthesizing the processed image pixel data. CONSTITUTION:A pixel string f<1>mn arranged of one half of an original image which is split by a separation means 201 is converted to a binary form by 'error diffusion method' in a bus proceeding from a data line 202 to a right-hand side. A pixel string f<2>mn of the other half is converted in terms of binary value by 'systematic dither method' in a bus from a data line 203 to a right-hand side. The pixel string f<1>mn becomes correction data f<1>mn by carrying in a correction value DELTAtmn from a data line 216 by means of an adder 206, and this correction data is supplied to a threshold value circuit 28 from a data line 207. In the circuit, said data is converted to a binary form and becomes dot data g<1>mn. The pixel string of the other half f<2>mn is sequentially compared to a threshold value tmn supplied from a data line 218 and then is converted to a binary form and, in turn, to dot data g<2>mn by a threshold value circuit 217. After this, the conversion results processed in parallel g<1>mn, g<2>mn are conducted to an output line 222 after synthesizing at a logic sum circuit 221, and the synthesized pixels are reconstructed into a final dot image 225.
|
