Method and Apparatus for Optimizing Memory Usage in Image Processing

• US 20090262208A1
• Filed: 04/21/2008
• Published: 10/22/2009
• Est. Priority Date: 04/21/2008
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Vitsnudel, Ilia
• Granted Patent: US 8,031,952 B2
• Time in Patent Office: Days
• US Class Current: 348/222.100
• CPC Class Codes: H04N 19/428 Recompression, e.g. by spatial or temporal decimation
• CPC Class Codes: H04N 19/547 Motion estimation performed in a transform domain
• CPC Class Codes: H04N 19/593 involving spatial prediction techniques
• CPC Class Codes: H04N 19/60 using transform coding
• CPC Class Codes: H04N 19/647 using significance based coding, e.g. Embedded Zerotrees of Wavelets [EZW] or Set Partitioning in Hierarchical Trees [SPIHT]
• CPC Class Codes: H04N 23/80 Camera processing pipelines; Components thereof

Abstract

A method and digital camera avoiding the use of delay lines for block processing within the camera, such as compressing images, demosaicing, or the like. Processing is done for a block comprising a single newly received line, together with previously acquired information. In one preferred embodiment, the block processing is performed for the single line using previous lines as retrieved from the results of previous processing. In another embodiment, the processing results for the current block are determined by the processing results of the previous block together with the newly received line. Saving delay lines provides for lower memory requirements, and enables the production of smaller and lower cost cameras.

Claims

1. A method for processing a pixel block, the method comprising the steps of:

receiving data related to at least one previously captured image line, the data differing from the at least one previously captured image line;

receiving at least one captured pixel, the at least one captured pixel belonging to at least one captured image line; and

processing the at least one captured pixel and the data related to the at least one previously captured image line to obtain a processed block result.

2. The method of claim 1 wherein the pixel block is a rectangular pixel block.

3. The method of claim 1 further comprising a deprocessing step for deprocessing the processed block results to obtain at least one image line.

4. The method of claim 1 wherein the data related to the at least one previously captured image line is a reconstruction of the at least one previously captured image line.

5. The method of claim 1 wherein the data related to the at least one previously captured image line is an estimated reconstruction of the at least one previously captured image line.

6. The method of claim 1 wherein the data related to the at least one previously captured image line comprises a block processing result of an estimation of the at least one previously captured image line.

7. The method of claim 1 further comprising a storing step for storing the block processing results.

8. The method of claim 1 further comprising an error correction step for correcting an error in the processed block result.

9. The method of claim 1 wherein the processing step comprises an item selected from the group consisting of:

JPEG compression;

JPEG 2000 compression;

wavelet compression;

MPEG compression; and

demosaicing.

10. The method of claim 3 wherein the deprocessing step comprises an item selected from the group consisting of:

JPEG decompression;

JPEG 2000 decompression;

wavelet decompression;

MPEG decompression; and

mosaicing.

11. The method of claim 1 wherein the processing step is JPEG compression, and wherein JPEG coefficients are determined by rotating previous JPEG coefficients, subtracting a normalized value of an outdated pixel and adding a normalized value of the at least one captured pixel.

12. The method of claim 1 wherein performed in an image processing device.

13. The method of claim 1 wherein performed in a digital camera.

14. A method for processing a pixel block using a reduced number of delay lines, the method comprising the steps of:

receiving data related to previously captured at least one image line;

receiving at least one captured pixel, the at least one captured pixel belonging to a single captured image line; and

processing the at least one captured pixel and the data related to the previously captured at least one image line to obtain a processed block result.

15. An image processing device for processing a pixel block, the device comprising:

a memory unit comprising a delay line for storing at least one image line;

a processor for executing a processing engine for processing a pixel block comprising the at least one image line, from the delay line and from data related to at least one previously captured image line, for obtaining a processed block result.

16. The image processing device of claim 15 wherein the pixel block is a rectangular pixel block.

17. The image processing device of claim 15 wherein the processor further executes a deprocessing engine for deprocessing the processed block results to obtain an estimation to the at least one previously captured image line.

18. The image processing device of claim 15 wherein the data related to previously captured at least one image line is a reconstruction of the at least one image line.

19. The image processing device of claim 15 wherein the data related to previously captured at least one image line is an estimated reconstruction of the at least one image line.

20. The image processing device of claim 15 wherein the data related to the previously captured at least one image line comprises a block processing result of an estimation of the at least one previously captured image line.

21. The image processing device of claim 15 further comprising a storage device for storing the block processing results.

22. The image processing device of claim 15 wherein the processor further executes error detection and correction in the at least one image line.

23. The image processing device of claim 15 wherein the processing engine performs an item selected from the group consisting of:

JPEG compression;

JPEG 2000 compression;

wavelet compression;

MPEG compression; and

demosaicing.

24. The image processing device of claim 17 wherein the deprocessing engine performs an item selected from the group consisting of:

JPEG decompression;

JPEG 2000 decompression;

wavelet decompression;

MPEG decompression; and

mosaicing.

25. The image processing device of claim 15 wherein the processing engine performs JPEG compression, and wherein JPEG coefficients are determined by rotating previous JPEG coefficients, subtracting a normalized value of an outdated pixel and adding a normalized value of the at least one captured pixel.

26. A computer readable storage medium containing a set of computer instructions the set of computer instructions comprising:

receiving data related to at least one previously captured image line, the data differing from the previously captured at least one image line;

receiving at least one captured pixel, the at least one captured pixel belonging to at least one captured image lines; and

processing the at least one captured pixel and the data related to the at least one previously captured image line to obtain a processed block result.