Method and apparatus for on-line data enhancement

• US 4,365,304 A
• Filed: 07/16/1980
• Issued: 12/21/1982
• Est. Priority Date: 08/27/1979
• Status: Expired due to Term

• Current Assignee: Yeda Research and Development Co. Ltd. (Weizmann Institute of Science)
• Original Assignee: Yeda Research and Development Co. Ltd. (Weizmann Institute of Science)
• Inventors: Orbach, Zvi, Ruhman, Smil
• Primary Examiner(s): Smith, Jerry
• Application Number:
  US06/169,490
• Time in Patent Office: 888 Days
• Field of Search: 364/515, 364/553, 358/37, 358/166, 358/284
• US Class Current: 382/169
• CPC Class Codes: G06T 5/40 using histogram techniques
• CPC Class Codes: G06T 5/92 based on global image properties

Abstract

Apparatus for on-line data enhancement including apparatus for receiving data, apparatus for applying a histogram transformation to the received data including a look-up table embodied in a rewritable memory; apparatus for determining the histogram transformation in response to a histogram of the received data; and apparatus for producing a histogram of the received data.

Claims

1. Apparatus for on-line data enhancement comprising:

means for receiving input data;

means for gathering a histogram of said input data;

means for providing a histogram transformation function operative to convert said input data to output data having a desired one of a plurality of selectable output histograms, said plurality of selectable output histograms including non-flat histograms; and

a look up table for applying said histogram transformation function to said input data.

2. Apparatus according to claim 1 and wherein said data comprises image data.

3. Apparatus according to claim 2 and also comprising controllable means for selectably determining what portion of the input data is subject to transformation and selectable bypass means for bypassing said look-up table, said controllable means producing an output signal to said bypass means for defining a selectable window extending over at least part of an image, within which window image data is subject to transformation and outside of which window image data is not subject to transformation and bypasses said look-up table.

4. Apparatus according to claim 3 and wherein said means for selectably determining also determines what portion of the image data is used for determining the histogram transformation function and provides an output signal indicating said window to said providing means.

5. Apparatus according to claim 1 and wherein said look-up table is embodied in a rewritable memory.

6. Apparatus according to claim 1 and wherein said means for providing said histogram transformation function comprises means for periodically updating said transformation function.

7. Apparatus according to claim 1 and wherein said means for providing comprises means for sampling said received data and basing said histogram transformation function on said sampling.

8. Apparatus according to claim 1 and also comprising microprocessor control apparatus for governing the operation thereof.

9. Apparatus according to claim 1 and wherein said providing means also comprises means for data compression.

10. Apparatus according to claim 1 and wherein said providing means also comprises means for adaptive quantization.

11. Apparatus according to claim 1 and wherein said providing means also comprises means for bit truncation.

12. Apparatus according to claim 1 and wherein said data is video image data.

13. Apparatus according to claim 1 and wherein said means for gathering includes selectably operable means for gathering a histogram over a selectable number of fields.

14. A method for applying a histogram transformation to received data comprising the steps of:

receiving input data;

gathering a histogram of said input data;

providing a histogram transformation function operative to convert said input data to output data having a desired one of a plurality of selectable output histograms, said plurality of selectable output histograms including non-flat histograms;

inserting said histogram transformation function into a look-up table embodied in a rewritable memory; and

applying said input data to said look-up table for desired histogram transformation thereof.

15. A method according to claim 14 and also comprising the step of compressing the input data.

16. A method according to claim 14 and also comprising the step of truncating bits of said input data.

17. A method according to claim 14 and also comprising the step of limiting the application of the histogram transformation to a selected portion of the received data.

18. A method according to claim 14 and wherein said data is image data.

19. A method according to claim 14 and wherein said data is video image data.