Methods and systems for processing documents using multiple halftone screening techniques

• US 10,425,558 B2
• Filed: 12/01/2017
• Issued: 09/24/2019
• Est. Priority Date: 12/02/2016
• Status: Active Grant

• Current Assignee: Global Graphics Software, Inc. (Global Graphics Plc)
• Original Assignee: Global Graphics Software, Inc. (Global Graphics Plc)
• Inventors: Cook, Daniel J.
• Primary Examiner(s): Rogers, Scott A
• Application Number:
  US15/829,681
• Publication Number:
  US 20180160011A1
• Time in Patent Office: 662 Days
• CPC Class Codes: G06K 15/1881 Halftoning halftoning of still images in general H04N1/405, H04N1/52
• CPC Class Codes: H04N 1/40062 Discrimination between different image types, e.g. two-tone, continuous tone
• CPC Class Codes: H04N 1/4052 by error diffusion, i.e. transferring the binarising error to neighbouring dot decisions
• CPC Class Codes: H04N 1/4057 the pattern being a mixture of differently sized sub-patterns, e.g. spots having only a few different diameters multi-toning H04N1/40087
• CPC Class Codes: H04N 2201/0082 Image hardcopy reproducer H04N2201/0091 - H04N2201/0094 take precedence

Abstract

A method of processing a document for printing includes receiving a document; for at least one of the plurality of regions, determining a drop size for that region and determining whether the drop size for printing the region meets a threshold criterion and, if so, processing the region using a tile-based screen for halftoning and, if not, processing the region using an error diffusion screen for halftoning; and printing the processed regions. Another method includes additionally considering coverage level to determine whether to use a tile-based screen or error diffusion screen. Yet another method includes determining whether the region is within a threshold range of a drop step change.

Claims

1. A method of processing a document for printing;

the method comprising;

receiving a document;

for each of a plurality of regions of the document,

determining a drop size for printing the region, and

determining whether the drop size for printing the region meets a first threshold criterion and, if so, processing the region using a tile-based screen for halftoning, otherwise determining whether a coverage level for printing the region meets a second threshold criterion and, if so, processing the region using a tile-based screen for halftoning and, if not, processing the region using an error diffusion screen for halftoning; and

printing the processed regions.

2. The method of claim 1, wherein the first threshold criterion is that the drop size is not the smallest drop size.

3. The method of claim 1, wherein the second threshold criterion is that the coverage level is at or above a threshold coverage level.

4. The method of claim 1, wherein the tile-based screen is a threshold screen.

5. The method of claim 4, wherein the threshold screen utilizes at least one lookup array of threshold values.

6. The method of claim 1, wherein the first threshold criterion is that the drop size is not one of the smallest two drop sizes.

7. The method of claim 1, wherein the first threshold criterion is that the drop size is not one of the smallest three drop sizes.

8. The method of claim 1, wherein the first threshold criterion is that the drop size is not one of the smallest four drop sizes.

9. The method of claim 1, wherein the second threshold criterion is that the coverage level is above a threshold coverage level.

10. The method of claim 1, wherein the second threshold criterion is that the coverage level is at or below a threshold coverage level.

11. The method of claim 1, wherein the second threshold criterion is that the coverage level is below a threshold coverage level.

12. A system for processing a document for printing, the system comprising:

at least one processor configured and arranged to perform the method of claim 1.

13. A non-transitory computer-readable medium having processor-executable instructions for processing documents, the processor-executable instructions when installed onto a device enable the device to perform the method of claim 1.

14. A method of processing a document for printing;

the method comprising;

receiving a document;

for each of a plurality of regions of the document, determining whether the region is within a threshold range of a drop step change and, if so, processing the region using a tile-based screen for halftoning and, if not, processing the region using an error diffusion screen for halftoning, wherein the threshold range is a physical distance on media or a number of pixels; and

printing the processed regions.

15. The method of claim 14, wherein the tile-based screen is a threshold screen.

16. The method of claim 14, wherein the threshold screen utilizes at least one lookup array of threshold values.

17. The method of claim 14, wherein the threshold range is the physical distance on the media.

18. The method of claim 14, wherein the threshold range is the number of pixels.

19. A system for processing a document for printing, the system comprising:

at least one processor configured and arranged to perform the method of claim 14.

20. A non-transitory computer-readable medium having processor-executable instructions for processing documents, the processor-executable instructions when installed onto a device enable the device to perform the method of claim 14.