发明名称 Bi-level digital color printer system exhibiting improved undercolor removal and error diffusion procedures
摘要 A system selectively enables a printer to deposit on a sheet C, M, Y and K color dots at each of the plurality of pixel locations to produce a color image. The system comprises a memory for storing C, M, Y and K color values for each pixel in the color image and a processor for controlling selective deposition of the C, M, Y and K colors. The processor determines a gray value for each pixel location from values stored in the C, M, and Y color planes. The processor subtracts the determined gray value from the C, M, and Y values which correspond to the pixel location and then determines a relationship of the gray value to a non-linear function and in dependence upon the relationship alters the C, M and Y pixel values accordingly. The processor either (1) adds the gray value back to the C, M, and Y values for the pixel location, or (2) adds a first portion of the gray value to the C, M, and Y values for the pixel location and a second portion of the gray value to the K value for the pixel location; or (3) adds all of the gray value to a K value for the pixel location. As a result, the C, M, Y and K values are altered in accordance with the determined gray value. The altered color values are then prioritized and the processor determines which colors should be printed at each pixel location and diffuses color error values to neighboring pixel locations after such determination. The prioritization procedure enables print priority to be given to either the brightest color dot or to the color dot that is most visible to the human eye.
申请公布号 US5402245(A) 申请公布日期 1995.03.28
申请号 US19940187567 申请日期 1994.01.27
申请人 HEWLETT-PACKARD COMPANY 发明人 MOTTA, RICARDO J.;FITZHUGH, ANDREW E.;MCGUIRE, MICHAEL D.;DISPOTO, GARY J.
分类号 B41J2/21;B41J2/525;H04N1/52;H04N1/60;(IPC1-7):H04N1/21 主分类号 B41J2/21
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