Device state error diffusion technique for halftoning
 A halftoning technique is disclosed which uses look-up tables to identify a combination of color ink drops (device states) to be printed by an inkjet printer. The look-up tables are indexed by a particular color to be reproduced. An error is also output by the look-up tables reflecting the difference between the indexing tone level and the printed color spot. The error is applied in a halftoning process to neighboring pixels. A plurality of look-up tables is used, and one of the look-up tables is selected for a particular medium (e.g., glossy paper, plain paper) to be printed upon. In this manner, the number and combination of ink drops can be optimize for a particular type of medium. In one embodiment, six different color inks are used by the printer. 
Hewlett-Packard Company
H G
H04N G06F
inventional inventional
Guo Francis E.
Li Bockman