METHOD AND APPARATUS FOR DISPLAYING GRAYSCALE DATA ON A MONOCHROME GRAPHIC DISPLAY

摘要

A time-domain graphic synthesis method and apparatus form M single-bit patterns of length N to convert multiple-bit grayscale pixel data into single-bit binary display signals. M designates the number of gray levels to be displayed. N specifies a selected pattern size for usage in converting gray levels into perceived grayscale pixel data and advantages are gained if N is defined to be a prime number. Each of the N-bit binary patterns identifies a particular gray shade and each pattern, by definition, includes a plurality of ones and zeros. The ratio of the number of ones in an N-bit pattern to the total number N defines a relative intensity for that N-bit pattern. The relative intensity is indicative of and corresponds to the particular gray shade. The M single-bit patterns of length N are applied to a display which stores multiple-bit grayscale pixel data so that the column location of a pixel is converted to modulo-N form to designate one of the N bits of the pattern. Furthermore, for successive rows of the display, the column location of a pattern is progressively shifted or rotated with respect to a pixel. The shifting is modulo-N shifting and the amount of shifting is selected so that all N column locations are selected for N successive rows of the display. By applying the N-bit patterns in this manner, processing of all elements of the display includes processing of a matrix of adjacent NxN-bit squares. Processing of consecutive time frames of the display also includes shifting or rotating on a frame-by-frame basis, generating a repetitive pattern of N frames.