Print engine/controller with color mask

1. A print engine/controller to drive an ink drop print head comprising:

an interface at which to receive compressed page data;

decoders to decode respective types of image planes in the received compressed page data; and

a half-toner/compositor to composite image plane data;

the half-toner/compositor including:

a dot merger unit taking bits from the respective planes as inputs; and

a color mask register holding masking bits in number equal to the number of image planes;

respective input bits to the dot merger unit being ANDed with respective color mask register bits and the resultant bits Ored together to form an output bit in a channel for which there is an ink at the print head.

2. A print engine/controller as claimed in claim 1 wherein the respective planes to the dot merger unit include three contone color planes and a high resolution plane and the color mask register is loaded with bits that are selected to place the high resolution plane into any one of the respective color channels.

3. A print engine/controller as claimed in claim 2 wherein a fixative channel is generated from any one or more of the respective planes and selected by what bits are loaded to the color mask register.

4. A print engine/controller as claimed in claim 1 wherein the color mask register is loaded with bits that are selected to split a K plane into C, M, and Y channels for output to a print head without K.

5. A print engine/controller as claimed in claim 1 wherein the half-toner compositor includes a tag encoder generating an infrared tag data plane and the color mask register maps its dots into an infrared channel at the print head.

6. A print engine/controller to drive an ink drop print head comprising:

a contone image decoder to decode any compressed continuous tone image planes in the received compressed page data;

a high resolution image decoder to decode any compressed high resolution image plane; and

a halftoner/compositor including a dot merger unit controlled by a color mask to map image planes into channels corresponding to what inks are supplied in the print head that is interfaced by the print engine/controller.

7. A print engine/controller to drive an ink drop print head comprising:

a contone image decoder to decode any compressed continuous tone image planes in the received compressed page data;

a high resolution decoder to decode any compressed high resolution image plane; and

a halftoner/compositor including:

a margin unit to apply margin data to the respective image planes during the composite process; and

a dot merger unit controlled by a color mask to map image planes into channels corresponding to what inks are supplied in the print head that is interfaced by the print engine/controller.

8. A print engine/controller chip to interface with an ink drop print head comprising:

an interface at which to receive compressed page data;

a contone image decoder to decode any continuous tone image planes in the received compressed page data;

a high resolution decoder to decode any high resolution image plane in the received compressed page data;

a half-toner/compositor including to dither any continuous tone image planes and composite any high resolution image plane data with any output plane including a dot merger unit controlled by a color mask to map image planes into channels corresponding to what inks are supplied in the print head that is interfaced by the print engine/controller; and

a print head driver to output the composite to a print head.

9. An ink drop printer driven by a print engine/controller comprising:

an interface at which to receive compressed page data;

a contone image decoder to decode any continuous tone image planes in the received compressed page data;

a high resolution image decoder to decode any high resolution image planes in the received compressed page data;

a half-toner/compositor to dither any continuous tone image planes and composite high resolution image plane data with any output plane including a dot merger unit controlled by a color mask to map image planes into channels corresponding to what inks are supplied in the print head that is interfaced by the print engine/controller; and

a print head driver to output the composite to a print head; and

a print head.

10. A method of operating an ink drop printer comprising:

receiving compressed page data;

decoding any continuous tone image planes in the received compressed page data to generate output planes;

decoding any high resolution image plane in the received compressed page data to generate an output plane;

dithering any continuous tone image planes;

compositing any high resolution image plane data with any output plane; and

forwarding composited data to a print head with image planes mapped to what inks are available at the print head.