Printing color images on color printers and displaying them on computer mon
itors requires a significant reduction of physically distinct colors, which
causes degradation in image quality. An efficient method to improve the di
splay quality of a quantized image is error diffusion, which works by distr
ibuting the previous quantization errors to neighboring pixels, exploiting
the eye's averaging of colors in the neighborhood of the point of interest.
This creates the illusion of more colors. A new error diffusion method is
presented in which the adaptive recursive least-squares (RLS) algorithm is
used. This algorithm provides local optimization of the error diffusion fil
ter along with smoothing of the filter coefficients in a neighborhood. To i
mprove the performance, a diagonal scan is used in processing the image, (C
) 2000 Society of Photo-Optical Instrumentation Engineers. [S0091-3286(00)0
0611-5].