Flexible print data compression

• US 7,675,646 B2
• Filed: 05/31/2005
• Issued: 03/09/2010
• Est. Priority Date: 05/31/2005
• Status: Expired due to Fees

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: McGuinness, William F.
• Primary Examiner(s): Williams; Kimberly A
• Application Number:
  US11/140,798
• Publication Number:
  US 20060268322A1
• Time in Patent Office: 1,743 Days
• Field of Search: 382232-253, 358/1.15, 358/426.13, 358/426.14
• US Class Current: 358/1.2
• CPC Class Codes: G06F 3/1206 resulting in increased flexibility in input data format or job format or job type
• CPC Class Codes: G06F 3/1245 by conversion to intermediate or common format
• CPC Class Codes: G06F 3/1285 Remote printer device, e.g. being remote from client or server

Abstract

Methods for evaluating whether to compress data sent to a print device receive bands of printing data. Each band of printing data comprises a plurality of lines of printing data. A subset of lines of printing data comprising less than all of the lines of printing data is selected and a compression methodology is applied to the subset of lines of printing data to produce a partial compression ratio. The partial compression ratio is extrapolated to a full compression ratio based on a previously performed hardware compression. Then, an evaluation of whether to use the compression methodology on all of the lines of printing data can be performed based on the full compression ratio.

Claims

1. A machine-implemented method comprising:

receiving, using a controller, bands of printing data, wherein each band of printing data comprises a plurality of lines of printing data;

randomly selecting, using said controller, a subset of bands and randomly selecting a subset of lines of printing data comprising less than all of said lines of printing data;

applying, using said controller, a compression methodology to said subset of lines of printing data to produce a partial compression ratio;

extrapolating, using said controller, said partial compression ratio to a full compression ratio; and

evaluating, using said controller, whether to use said compression methodology on all of said lines of printing data based on said full compression ratio, wherein said randomly selecting of said subset of bands and said subset of lines of printing data comprises randomly selecting a group of spatially diverse lines within said bands of printing data.

2. The method according to claim 1, wherein said evaluating process comprises determining whether said full compression ratio is above a predetermined value.

3. The method according to claim 1, further comprising, prior to selecting said subset of lines of printing data, performing a hardware compression methodology adapted to prepare said lines of printing data to be stored on a fixed medium.

4. The method according to claim 1, wherein said compression methodology comprises a printer compression methodology adapted to prepare data to be processed by a printer.

5. A machine-implemented method comprising:

receiving, using a controller, bands of printing data, wherein each band of printing data comprises a plurality of lines of printing data;

performing a first compressing process comprising applying a first compression methodology to all of said bands of printing data, wherein said first compressing process produces a first full compression ratio;

selecting, using said controller, a subset of lines of printing data comprising less than all of said lines of printing data;

performing a second compressing process comprising applying a second compression methodology to said subset of lines of printing data to produce a partial compression ratio;

extrapolating, using said controller, said partial compression ratio to a second full compression ratio based on said first full compression ratio; and

evaluating, using said controller, whether to use said second compression methodology on all of said lines of printing data based on said second full compression ratio.

6. The method according to claim 5, wherein said selecting of said subset of lines of printing data comprises selecting a group of spatially diverse lines within said bands of printing data.

7. The method according to claim 5, wherein said evaluating process comprises determining whether said second full compression ratio is above a predetermined value.

8. The method according to claim 5, wherein said first compression methodology comprises a hardware compression methodology adapted to prepare said lines of data to be stored on a fixed medium.

9. The method according to claim 5, wherein said second compression methodology comprises a printer compression methodology adapted to prepare data to be processed by a printer.

10. A machine-implemented method comprising:

receiving, using a controller, bands of printing data, wherein each band of printing data comprises a plurality of lines of printing data;

performing a first compressing process comprising applying a first compression methodology to all of said bands of printing data, wherein said first compressing process produces a first full compression ratio;

selecting, using said controller, a subset of lines of printing data comprising less than all of said lines of printing data;

obtaining, using said controller, a band compression ratio from said first compression process for a band containing said subset of lines of printing data;

performing a second compressing process comprising applying a second compression methodology to said subset of lines of printing data to produce a partial compression ratio;

extrapolating, using said controller, said partial compression ratio to a second full compression ratio based on a relationship between said first full compression ratio and said band compression ratio; and

evaluating, using said controller, whether to use said second compression methodology on all of said lines of printing data based on said second full compression ratio.

11. The method according to claim 10, wherein said selecting of said subset of lines of printing data comprises selecting a group of spatially diverse lines within said bands of printing data.

12. The method according to claim 10, wherein said evaluating process comprises determining whether said second full compression ratio is above a predetermined value.

13. The method according to claim 10, wherein said first compression methodology comprises a hardware compression methodology adapted to prepare said lines of data to be stored on a fixed medium.

14. The method according to claim 10, wherein said second compression methodology comprises a printer compression methodology adapted to prepare data to be processed by a printer.

15. A machine-implemented method comprising:

receiving, using said controller, bands of printing data, wherein each band of printing data comprises a plurality of lines of printing data;

performing a first compressing process comprising applying a hardware compression methodology to all of said bands of printing data, wherein said first compressing process produces a first full compression ratio;

selecting, using said controller, a subset of lines of printing data comprising less than all of said lines of printing data;

obtaining, using said controller, a band compression ratio from said first compression process for a band containing said subset of lines of printing data;

performing a second compressing process comprising applying a software compression methodology to said subset of lines of printing data to produce a partial compression ratio;

extrapolating, using said controller, said partial compression ratio to a second full compression ratio based on a relationship between said first full compression ratio and said band compression ratio; and

evaluating, using said controller, whether to use said software compression methodology on all of said lines of printing data based on said second full compression ratio.

16. The method according to claim 15, wherein said selecting of said subset of lines of printing data comprises selecting a group of spatially diverse lines within said bands of printing data.

17. The method according to claim 15, wherein said evaluating process comprises determining whether said second full compression ratio is above a predetermined value.

18. The method according to claim 15, wherein said hardware compression methodology is adapted to prepare said lines of data to be stored on a fixed medium.

19. The method according to claim 15, wherein said software compression methodology is adapted to prepare data to be processed by a printer.