Balancing compressed storage requirements with decompression times during punt protection processing in a page printer

• US 5,999,272 A
• Filed: 10/20/1998
• Issued: 12/07/1999
• Est. Priority Date: 10/20/1998
• Status: Expired due to Term

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: Blair, Timothy P., Dow, Richard M., Mellor, Douglas J.
• Primary Examiner(s): Grant, II, Jerome
• Application Number:
  US09/175,903
• Time in Patent Office: 413 Days
• Field of Search: 395/114, 395/113, 395/116, 382/232, 358/10.15, 358/10.14, 358/10.17, 358/426, 358/261.3
• US Class Current: 358/1.15
• CPC Class Codes: G06F 3/122 with regard to computing resources, e.g. memory, CPU
• CPC Class Codes: G06F 3/1247 by conversion to printer ready format
• CPC Class Codes: G06F 3/1285 Remote printer device, e.g. being remote from client or server
• CPC Class Codes: G06F 3/1296 Printer job scheduling or printer resource handling
• CPC Class Codes: G06F 3/1297 Printer code translation, conversion, emulation, compression; Configuration of printer parameters

Abstract

An imaging device and method optimize memory usage during a print overrun avoidance operation by employing selected compression schemes upon page bands while ensuring that required decompression times of the bands are met for subsequent rendering purposes. A preferred method includes compressing a band from a page of image data and, if an estimated decompression time for the compressed band does not satisfy a race-the-laser threshold for subsequent video imaging, then decompressing the band and measuring an actual decompression time. If the actual decompression time satisfies the race-the-laser threshold, then the method includes keeping the compressed band for subsequent video imaging. On the other hand, if the actual decompression time does not satisfy the race-the-laser threshold, then the band is re-compressed using an alternate compression scheme and re-evaluated similar to the originally compressed band to determine whether the recompressed band'"'"'s decompression time will satisfy the race-the-laser threshold.

Claims

1. A method of image processing in an imaging device, the method comprising:

(a) compressing a band from a page of image data;

(b) if an estimated decompression time for the compressed band does not satisfy a race-the-laser threshold for subsequent video imaging, then decompressing the band and measuring an actual decompression time; and

,

(c) if the actual decompression time satisfies the race-the-laser threshold, then keeping the compressed band for subsequent video imaging.

2. The method of claim 1 further including pre-rasterizing the band prior to compressing the band.

3. The method of claim 1 further including estimating a decompression time for the compressed band subsequent to compressing the band and prior to determining if the estimated decompression time does not satisfy the race-the-laser threshold.

4. The method of claim 1 wherein decompressing the band occurs to a bit bucket such that the compressed band remains intact.

5. The method of claim 1 further including, if the estimated decompression time satisfies the race-the-laser threshold, then keeping the compressed band for subsequent video imaging without actually decompressing the band before the band is ready to be imaged.

6. The method of claim 1 further including, if the actual decompression time does not satisfy the race-the-laser threshold, then re-compressing the band using an alternate compression method, and repeating steps (b) and (c) as necessary for the band compressed with the alternate compression method.

7. The method of claim 1 wherein the imaging device is a printer, copier or facsimile machine.

8. A computer-readable medium having computer-executable instructions for performing steps in the method recited in claim 1.

9. A method of punt protection processing in an imaging device, the method comprising:

(a) pre-rasterizing a band from a page of image data;

(b) compressing the band;

(c) if a memory savings threshold is not achieved for the compressed band, then re-compressing the band using an alternate compression method;

(d) if a memory savings threshold is achieved for the compressed band, then estimating a decompression time for the compressed band;

(e) if the estimated decompression time does not satisfy a race-the-laser threshold for subsequent video imaging, then decompressing the band and measuring an actual decompression time; and

,

(f) if the actual decompression time satisfies the race-the-laser threshold, then keeping the compressed band for subsequent video imaging.

10. The method of claim 9 wherein decompressing the band occurs to a bit bucket such that the compressed band remains intact.

11. The method of claim 9 further including, if the estimated decompression time satisfies the race-the-laser threshold, then keeping the compressed band for subsequent video imaging without actually decompressing the band.

12. The method of claim 9 further including, if the actual decompression time does not satisfy the race-the-laser threshold, then re-compressing the band using an alternate compression method, and repeating steps (c), (d), (e) and (f) as necessary for the band compressed with the alternate compression method.

13. The method of claim 9 wherein the imaging device is a printer, copier or facsimile machine.

14. An imaging device comprising:

(a) a print engine;

(b) a memory operatively connected to the print engine for holding a compressed band from a page of image data;

(c) means for decompressing the compressed band and measuring an actual decompression time if an estimated decompression time for the compressed band does not satisfy a race-the-laser threshold for subsequent video imaging; and

,

(d) means for video imaging the compressed band if the actual decompression time satisfies the race-the-laser threshold.

15. The imaging device of claim 14 wherein the imaging device is a printer, copier or facsimile machine.

16. The imaging device of claim 14 wherein the compressed band is a pre-rasterized compressed band.

17. The imaging device of claim 14 further including means for determining the estimated decompression time for the compressed band.

18. The imaging device of claim 14 wherein the means for decompressing includes means for decompressing to a bit bucket such that the compressed band remains intact.

19. The imaging device of claim 14 further including means for decompressing and video imaging the compressed band if the estimated decompression time for the compressed band satisfies the race-the-laser threshold.

20. The imaging device of claim 14 further including means for re-compressing the band using an alternate compression method after decompressing the compressed band if the actual decompression time does not satisfy the race-the-laser threshold, and further including means for submitting the re-compressed band for processing by means elements (c) and (d) as necessary.

21. The imaging device of claim 14 further including means for re-compressing the band using an alternate compression method if the compressed band does not satisfy a memory savings threshold.