Method and apparatus for improving the performance of a host-based color printing system

1. A color printing accelerator module for use with a host computer of a host-based color printing system, wherein the host computer is adapted to communicate image data from a first I/O port of the host computer to a corresponding I/O port of a printer, the image data communicated from the host computer to the printer including raster image data, the color printing accelerator module comprising:

an I/O interface configured to communicate with a second I/O interface of the host computer, wherein the color printing accelerator module functions as a peripheral device solely of the host computer through the I/O interface;

image processing logic including print quality processing logic in communication with the I/O interface, the image processing logic including print quality processing logic configured to perform print quality processing on first color space image data converted by the host computer from image data in a second color space, where the image data in the second color space is received at the I/O interface from the second I/O interface of the host computer; and

wherein image data processed by the image processing logic is communicated to the I/O interface for transmission to the second I/O interface of the host computer for use by the host computer in generating the raster image data that is provided from the first I/O port of the host computer to the corresponding port of the printer.

2. The color printing accelerator module of claim 1 , further comprising:

halftoning logic that receives data from the print quality processing logic that has been processed by the print quality processing logic, the halftoning logic being configured to perform halftoning on the print quality processed data.

3. The color printing accelerator module of claim 1 , wherein the I/O interface of the color printing accelerator module comprises a Universal Serial Bus (USB) interface for connection with a corresponding USB port of the host computer.

4. The color printing accelerator module of claim 1 , wherein the I/O interface of the color printing accelerator module is a Peripheral Component Interconnect (PCI)-Express interface for connection with a corresponding PCI-Express port of the host computer.

5. The color printing accelerator module of claim 1 , wherein image data is compressed by the host computer and provided to the first I/O port of the host computer to the corresponding I/O port of the printer as the raster image data.

6. A host-based color printing system comprising:

a host computer including a color space converter adapted to convert image data from a first color space to a second color space, wherein the host computer includes a first input/output (I/O) port and a second I/O port, where the second I/O port is adapted to communicate image data to a corresponding port of a printer, the image data communicated by the host computer to the printer including raster image data; and

a color printing accelerator module having an I/O interface connected to the first I/O port of the host computer to provide a communication link that facilitates connection of the color printing accelerator module so that the color printing accelerator module functions as a peripheral device solely of the host computer, the color printing accelerator module having image processing logic to process the second color space image data received at the I/O interface of the color printing accelerator module from the first I/O port of the host computer, where the image processing logic communicates image data that it has processed to the I/O interface of the color printing accelerator module for transmission to the first I/O port of the host computer over the communication link, wherein the host computer uses processed image data received from the color printing accelerator module to generate the raster image data communicated to the printer.

7. The host-based color printing system of claim 6 , wherein the image processing logic of the color printing accelerator module comprises:

print quality processing logic that receives color converted image data from the I/O interface of the color printing accelerator module, the print quality processing logic being configured to perform print quality processing on the color converted image data received from the I/O interface of the color printing accelerator module.

8. The host-based color printing system of claim 7 , wherein the image processing logic of the color printing accelerator module further comprises:

halftoning logic that receives print quality processed data from the print quality processing logic, the halftoning logic being configured to perform halftoning on the print quality processed data received by the halftoning logic to thereby provide halftoned processed data.

9. The host-based color printing system of claim 6 , wherein the I/O interface of the color printing accelerator module is a Universal Serial Bus (USB) interface and the first I/O port of the host computer is a USB port.

10. The host-based color printing system of claim 6 , wherein the I/O interface of the color printing accelerator module is a Peripheral Component Interconnect (PCI)-Express interface and the first I/O port of the host computer is a PCI-Express port.

11. The host-based color printing system of claim 7 , wherein the color space converter of the host computer performs color space conversion on data associated with a print job to convert red, green, blue (RGB) data into cyan, magenta, yellow and black (CMYK) data, wherein the color converted image data received at the I/O interface of the color printing accelerator module is CMYK data transferred from the host computer to the color printing accelerator module over said communication link, and wherein print quality processed image data that has been print quality processed by the print quality processing logic is transferred from the color printing accelerator module to the host computer over said communication link, and wherein the host computer performs halftoning on the print quality processed image data transferred from the color printing accelerator module to the host computer.

12. The host-based color printing system of claim 8 , wherein, after the data has been halftoned, the host computer performs data compression on the halftoned processed data and sends the compressed data as the raster image data to the printer over the second I/O interface of the host computer.

13. The host-based color printing system of claim 8 , wherein the color space converter of the host computer performs color space conversion on data associated with a print job to convert red, green, blue (RGB) data into cyan, magenta, yellow and black (CMYK) data, wherein the color space converted image data received by the I/O interface of the color printing accelerator module is CMYK data transferred from the host computer to the color printing accelerator module over said communication link, and wherein after halftoning has been performed, the halftoned data is sent from the color printing accelerator module to the host computer over said communication link, and wherein the host computer performs data compression on the processed halftoned data.

14. The host-based color printing system of claim 13 , wherein the host computer sends the compressed image data as the raster image data to the printer over the second I/O interface of the host computer.

15. The host-based color printing system of claim 6 , wherein image data is compressed by the host computer and communicated to the printer as the raster image data.

16. A method for performing color printing in a host-based color printing system, the method comprising:

in a host computer of the host-based color printing system, performing color space conversion on data associated with a print job to convert red, green, blue (RGB) data into cyan, magenta, yellow and black (CMYK) data;

sending the CMYK data over an input/output (I/O) interface of the host computer to an I/O interface of a color printing accelerator module;

in the color printing accelerator module, performing an image processing operation on the CMYK data sent to the color printing accelerator module, where the image processing operation is selected from a group of image processing operations comprising print quality processing, halftoning, and image data compression;

in the color printing accelerator module, sending image data that has been processed by the color printing accelerator module to the host computer;

in the host computer, performing a further image processing operation on the processed image data received from the color printing accelerator module, where the further image processing operation is selected from a group of image processing operations comprising halftoning and image data compression; and

in the host computer, sending the compressed raster image data from the host computer to a printer for printing.

17. The method of claim 16 , wherein halftoning is performed by halftoning logic in the color print accelerator module.

18. The method of claim 16 , wherein halftoning is performed by logic in the host computer.

19. The method of claim 18 , wherein the logic that performs halftoning comprises a processor and halftoning code which is executable by the processor.

20. The method of claim 18 , wherein the logic that performs halftoning is hardware.

21. The method of claim 16 , wherein data compression is performed by logic in the host computer.

22. The method of claim 16 , wherein data compression is performed by logic in the color printing accelerator module.