Digital Halftoning Methods R I for Selectively Partitioning Erro Nto Achromatic and Chromatic Channels N

f q A method is described for reducing the visibility of artifacts arising in the display o uantized color images on CRT displays. The method is based on the differential spatial senv sitivity of the human visual system to chromatic and achromatic modulations. Because the isual system has the highest spatial and temporal acuity for the luminance component of an i image, we seek a technique which will reduce luminance artifacts at the expense of introduc ng high-frequency chromatic errors. In this paper we explore a method based on controlling n the correlations between the quantization errors in the individual phosphor images. The lumi ance component is greatest when the phosphor errors are positively correlated, and is minimi ized when the phosphor errors are negatively correlated. The greatest effect of the correlation s obtained when the intensity quantization step sizes of the individual phosphors have equal y s luminances. For the ordered dither algorithm, a version of the method can be implemented b imply inverting the matrix of thresholds for one of the color components.