Multi-valued image data is separated into data in units of nozzle groups of the individual colors of a printhead, and each divided multi-valued image data is converted into n-valued image data consisting of a plurality of bits. Based on the n-valued image data of the corresponding colors, print codes...http://www.google.com.au/patents/US6158836?utm_source=gb-gplus-sharePatent US6158836 - Print method and apparatus
