Abstract: A method and apparatus for halftoning where at most one halftoned gray, or multi-level, pixel will occur in those halftone cells having a constant area of ink. The method and apparatus includes placing a threshold array and the pixel tonal values within the same range if the threshold array and pixel tonal values are in different ranges. The elements in the threshold array are then compared to the pixel tonal values in order to determine a resulting output value.The preferred apparatus for halftoning includes a memory for storing the threshold array; a multiplier for multiplying one 8-bit value representing the number of pixels in a halftone cell by a second 8-bit value which is a pixel tonal value; a comparator for comparing the results of the multiplier with an element from the threshold array; and a multiplexer for selecting a resulting output value based upon the output generated by the comparator.
Inventors:
Steven P. Jobs, Bartley K. Andre, Daniel J. Coster, Daniele De Iuliis, Richard P. Howarth, Jonathan P. Ive, Matthew Dean Rohrbach, Douglas B. Satzger, Calvin Q. Seid, Christopher J. Stringer
Inventors:
Steven P. Jobs, Bartley K. Andre, Daniel J. Coster, Daniele De Iuliis, Richard P. Howarth, Jonathan P. Ive, Matthew Dean Rohrbach, Douglas B. Satzger, Calvin Q. Seid, Christopher J. Stringer