Patent ID: 7583412

Claim:
A method for converting a contone-to-binary halftoning array to a contone-to-encoded pattern halftoning array, the contone-to-binary halftoning array having X by Y threshold values, the contone-to-binary halftoning array being configured to be used in image processing to convert an input contone array of contone data values to an output binary array of binary data values based on comparing each contone data value to each threshold value, wherein the comparison generates X by Y binary data values for each contone data value; the contone-to-encoded pattern halftoning array having M sets of pattern look-up tables, wherein M is one or more, the contone-to-encoded pattern halftoning array being configured to be used in image processing to convert an input contone array of contone data values to an output encoded array of pattern values based on comparing each of the contone data values to each set of pattern look-up tables, wherein the comparison generates M encoded pattern values for each contone data value and each encoded pattern value corresponds to a K by L multi-pixel pattern of binary data values in a library; the method comprising: replicating the X by Y threshold values into a replicated array that is evenly divisible by a K by L array; dividing the replicated array into K by L blocks of threshold values, wherein a number of K by L blocks is M; then, for each of 1 to N contone data values: (a) converting each of the K by L blocks of threshold values to a K by L binary array of binary data values based on comparing each contone data value to each threshold value to form a desired pattern in the block, (b) correlating the desired pattern in each block to a multi-pixel pattern in the library, and (c) entering a pattern value corresponding to the multi-pixel pattern in an array for each block to generate M sets of arrays; and then, after acts (a)-(c), compiling the M sets of arrays to populate the M sets of pattern look-up tables to create the contone-to-encoded pattern halftoning array.