Systems and methods for processing image data prior to compression

• US 7,539,341 B2
• Filed: 07/29/2004
• Issued: 05/26/2009
• Est. Priority Date: 07/29/2004
• Status: Active Grant

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Eschbach, Reiner, Rainero, Emil V.
• Primary Examiner(s): Wu, Jingge
• Assistant Examiner(s): Allison, Andrae S
• Application Number:
  US10/901,333
• Publication Number:
  US 20060023960A1
• Time in Patent Office: 1,762 Days
• Field of Search: 382/254, 382/162, 382/166, 382/239, 709/247, 709/202, 709/203, 715/526, 345/864
• US Class Current: 382/166
• CPC Class Codes: H04N 1/6027 Correction or control of colour gradation or colour contrast H04N1/6058 takes precedence
• CPC Class Codes: H04N 1/64 Systems for the transmission or the storage of the colour picture signal; Details therefor, e.g. coding or decoding means therefor H04N19/00 takes precedence
• CPC Class Codes: H04N 19/127 Prioritisation of hardware or computational resources
• CPC Class Codes: H04N 19/85 using pre-processing or post-processing specially adapted for video compression

Abstract

Systems and methods provide data processing before data compression. The data processing includes contrast enhancement and/or custom color mapping.

Claims

1. A system for processing an image for compression and transmission, the image having data associated therewith, the data having one or more data values and color levels, the data being subsequently compressed and transmitted, the system comprising:

a parameter selecting circuit, routine or application that determines one or more parameters for processing data associated with the image, the parameters associated with at least one of data compression and data transmission of the image,

wherein the parameter selecting circuit, routine or application determines at least one of a bandwidth of a network for subsequent data transmission, a transmission speed of the network, a data display zoom level, and a compressed image size;

a data enhancing circuit, routine or application that enhances a contrast of the data values, prior to compressing the processed data, based on the one or more parameters determined; and

a data compression circuit, routine or application that compresses data processed by the data processing circuit,

wherein the data processing circuit, routine or application increases a data compression ratio in the data compression.

2. The system according to claim 1, wherein the parameter selecting circuit, routine or application determines a compressed image size, and the data enhancing circuit, routine or application enhances the contrast of the data values based on the determined compressed image size.

3. The system according to claim 1, wherein the data enhancing circuit, routine or application reduces a number of color levels of the data values having enhanced contrast.

4. The system according to claim 1, wherein the parameter selecting circuit, routine or application determines a data display zoom level, and the data enhancing circuit, routine or application enhances the contrast of the data values based on the determined data display zoom level.

5. The system according to claim 3, wherein the data enhancing circuit, routine or application processes losslessly compressed color mapped data.

6. The system according to claim 5, the losslessly compressed color mapped data being graphics interchange format (GIF) data.

7. The system according to claim 1, wherein the data enhancing circuit, routine or application processes the data associated with the image using tonal reproduction curves to increase a number of correlated entries in the data, thereby increasing a data compression ratio in subsequent data compression.

8. The system according to claim 7, wherein different tonal reproduction curves are used for different levels of compression.

9. The system according to claim 8, wherein different types of tonal reproduction curves are used for different document types.

10. The system according to claim 7, wherein different types of tonal reproduction curves are used for different document types.

11. A computer-readable medium storing a computer program product tangibly embodying a program of instructions for processing an image for compression and transmission, the image having data associated therewith, the data having one or more data values and color levels, the instructions, when executed by a processor, causing the processor to perform operations comprising:

determining one or more parameters associated with at least one of data compression and data transmission of the image;

processing data associated with the image by enhancing a contrast of the data values, prior to compressing the processed data, based on the one or more parameters determined, wherein processing the data associated with the image comprises using tonal reproduction curves to increase a number of correlated entries in the data, thereby increasing a data compression ratio in subsequent data compression; and

compressing the processed data associated with the image.

12. The computer-readable medium according to claim 11, the operations further comprising reducing the number of color levels of the data values having enhanced contrast.

13. The computer-readable medium according to claim 11, wherein determining one or more parameters comprises determining at least one of a bandwidth of a network for subsequent data transmission, a transmission speed of the network, a data display zoom level, and a compressed image size.

14. The computer-readable medium according to claim 11, wherein determining one or more parameters comprises determining a data display zoom level, and wherein processing data associated with the image enhances the contrast of the data values based on the determined data display zoom level.

15. The computer readable medium according to claim 12, wherein reducing the number of the color levels comprises processing losslessly compressed color mapped data.

16. The computer readable medium according to claim 15, the losslessly compressed color mapped data being graphics interchange format (GIF) data.

17. The computer-readable medium according to claim 11, wherein different tonal reproduction curves are used for different levels of compression.

18. The computer-readable medium according to claim 17, wherein different types of tonal reproduction curves are used for different document types.

19. The computer-readable medium according to claim 11, wherein different types of tonal reproduction curves are used for different document types.

20. The computer-readable medium according to claim 12, wherein reducing the number of the color levels comprises performing color mapping to reduce the number of the color levels.

21. The computer-readable medium according to claim 11, wherein determining one or more parameters comprises determining a compressed image size, and wherein processing data associated with the image enhances the contrast of the data values based on the determined compressed image size.

22. A method for processing an image for compression and transmission, the image having data associated therewith, the data having one or more data values and color levels, the method comprising:

using a controller, the controller;

determining one or more parameters associated with at least one of data compression and data transmission of the image;

processing data associated with the image by enhancing a contrast of the data values, prior to compressing the processed data, based on the one or more parameters determined, wherein processing the data associated with the image comprises using tonal reproduction curves to increase a number of correlated entries in the data, thereby increasing a data compression ratio in subsequent data compression; and

compressing the processed data associated with the image.

23. The method of claim 22, further comprising reducing a number of the color levels of the data values having enhanced contrast.

24. The method of claim 22, wherein determining one or more parameters comprises determining at least one of a bandwidth of a network for subsequent data transmission, a transmission speed of the network, a data display zoom level, and a compressed image size.

25. The method of claim 22, wherein determining one or more parameters comprises determining a data display zoom level, and wherein processing data associated with the image enhances the contrast of the data values based on the determined data display zoom level.

26. The method of claim 23, wherein reducing the number of the color levels comprises processing losslessly compressed color mapped data.

27. The method of claim 26, the losslessly compressed color mapped data being graphics interchange format (GIF) data.

28. The method of claim 22, wherein different tonal reproduction curves are used for different levels of compression.

29. The method of claim 28, wherein different types of tonal reproduction curves are used for different document types.

30. The method of claim 29, wherein determining one or more parameters comprises determining a data display zoom level, and wherein processing data associated with the image enhances the contrast of the data values based on the determined data display zoom level.

31. The method of claim 29, wherein determining one or more parameters comprises determining a compressed image size, and wherein processing data associated with the image enhances the contrast of the data values based on the determined compressed image size.

32. The method of claim 22, wherein different types of tonal reproduction curves are used for different document types.

33. The method of claim 23, wherein reducing the number of the color levels comprises performing color mapping to reduce the number of the color levels.

34. The method of claim 22, wherein determining one or more parameters comprises determining a compressed image size, and wherein processing data associated with the image enhances the contrast of the data values based on the determined compressed image size.