Compression and decoding of single sensor color image data

• US 8,538,143 B2
• Filed: 11/21/2012
• Issued: 09/17/2013
• Est. Priority Date: 03/22/2006
• Status: Active Grant

• Current Assignee: GoPro, Inc.
• Original Assignee: GoPro, Inc.
• Inventors: Newman, David A.
• Primary Examiner(s): Tran, Phuoc
• Application Number:
  US13/683,965
• Publication Number:
  US 20130129211A1
• Time in Patent Office: 300 Days
• Field of Search: 382/166, 382/167, 382/233, 382/240, 382/260, 348/266, 348/267, 348/273, 348/280
• US Class Current: 382/166
• CPC Class Codes: G06F 3/0484 for the control of specific functions or operations, e.g. selecting or manipulating an object, an image or a displayed text element, setting a parameter value or selecting a range
• CPC Class Codes: G06T 9/00 Image coding bandwidth or redundancy reduction for static pictures H04N1/41; coding or decoding of static colour picture signals H04N1/64; methods or arrangements for coding, decoding, compressing or decompressing digital video signals H04N19/00
• CPC Class Codes: H04N 1/648 Transmitting or storing the primary (additive or subtractive) colour signals; Compression thereof H04N1/642 - H04N1/646 take precedence
• CPC Class Codes: H04N 19/117 Filters, e.g. for pre-processing or post-processing sub-band filter banks H04N19/635
• CPC Class Codes: H04N 19/136 Incoming video signal characteristics or properties
• CPC Class Codes: H04N 19/186 the unit being a colour or a chrominance component
• CPC Class Codes: H04N 19/44 Decoders specially adapted therefor, e.g. video decoders which are asymmetric with respect to the encoder
• CPC Class Codes: H04N 19/85 using pre-processing or post-processing specially adapted for video compression
• CPC Class Codes: H04N 23/667 Camera operation mode switching, e.g. between still and video, sport and normal or high- and low-resolution modes
• CPC Class Codes: H04N 5/265 Mixing

Abstract

A method is described to greatly improve the efficiency of and reduce the complexity of image compression when using single-sensor color imagers for video acquisition. The method in addition allows for this new image compression type to be compatible with existing video processing tools, improving the workflow for film and television production.

Claims

1. A method for compressing an image comprising:

accessing an image frame comprising a plurality of pixels, the plurality of pixels comprising a plurality of spatially-interleaved colors;

separating the plurality of pixels into a first color plane comprising a first set of pixel values of a first color, a second color plane comprising a second set of pixel values of a second color, and a third color plane comprising a third set of pixel values of a third color;

encoding a difference between each pixel value in the third set of pixel values multiplied by a factor of 2 and a sum of an associated pixel value in the first set of pixel values and an associated pixel value in the second set of pixel values into a modified image plane; and

storing the modified image plane in a memory.

2. The method of claim 1, wherein the first color and the second color comprise the same color.

3. The method of claim 2, wherein the third color comprises a different color than the first color and the second color.

4. The method of claim 3, wherein the first color and the second color comprise the color green.

5. The method of claim 4, wherein the third color comprises the color red.

6. The method of claim 4, wherein the third color comprises the color blue.

7. The method of claim 1, wherein the differences are encoded using a DCT or wavelet compression.

8. The method of claim 1, further comprising:

further separating the plurality of pixels into a fourth color plane comprising a fourth set of pixel values of a fourth color;

encoding a difference between each pixel value in the fourth set of pixel values multiplied by a factor of 2 and the sum of an associated pixel value in the first set of pixel values and an associated pixel value in the second set of pixel values into a second modified image plane; and

storing the second modified image plane in the memory.

9. The method of claim 8, further comprising:

encoding a sum of each pixel value in the first set of pixel values and an associated pixel value in the second set of pixel values into a third modified image plane;

encoding a difference between each pixel value in the first set of pixel values and an associated pixel value in the second set of pixel values into a fourth modified image plane; and

storing the third and fourth modified image planes in the memory.

10. The method of claim 9, further comprising:

decoding the modified image plane, the second modified image plane, the third modified image plane, and the fourth modified image plane into the first set of pixel values, the second set of pixel values, the third set of pixel values, and the fourth set of pixel values; and

combining the first set of pixel values, the second set of pixel values, the third set of pixel values, and the fourth set of pixel values to form the original image frame.

11. A system for compressing an image comprising:

a retrieval module configured to access an image frame comprising a plurality of pixels, the plurality of pixels comprising a plurality of spatially-interleaved colors;

a plane separation module configured to separate the plurality of pixels into a first color plane comprising a first set of pixel values of a first color, a second color plane comprising a second set of pixel values of a second color, and a third color plane comprising a third set of pixel values of a third color; and

an encoder configured to;

encode a difference between each pixel value in the third set of pixel values multiplied by a factor of 2 and a sum of an associated pixel value in the first set of pixel values and an associated pixel value in the second set of pixel values into a modified image plane; and

store the modified image plane in a memory.

12. The system of claim 11, wherein the first color and the second color comprise the same color.

13. The system of claim 12, wherein the third color comprises a different color than the first color and the second color.

14. The system of claim 13, wherein the first color and the second color comprise the color green.

15. The system of claim 14, wherein the third color comprises the color red.

16. The system of claim 14, wherein the third color comprises the color blue.

17. The system of claim 11, wherein the encoder encodes the differences using a DCT or wavelet compression.

18. The system of claim 11, wherein the plane separation module is further configured to separate the plurality of pixels into a fourth color plane comprising a fourth set of pixel values of a fourth color, and wherein the encoder is further configured to:

encode a difference between each pixel value in the fourth set of pixel values multiplied by a factor of 2 and the sum of an associated pixel value in the first set of pixel values and an associated pixel value in the second set of pixel values into a second modified image plane; and

store the second modified image plane in the memory.

19. The system of claim 18, wherein the encoder is further configured to:

encode a sum of each pixel value in the first set of pixel values and an associated pixel value in the second set of pixel values into a third modified image plane;

encode a difference between each pixel value in the first set of pixel values and an associated pixel value in the second set of pixel values into a fourth modified image plane; and

store the third and fourth modified image planes in the memory.

20. The system of claim 19, further comprising:

a decoder configured to;

decode the modified image plane, the second modified image plane, the third modified image plane, and the fourth modified image plane into the first set of pixel values, the second set of pixel values, the third set of pixel values, and the fourth set of pixel values; and

combine the first set of pixel values, the second set of pixel values, the third set of pixel values, and the fourth set of pixel values to form the original image frame.