SYSTEMS AND METHODS FOR YCC IMAGE PROCESSING

• US 20130322746A1
• Filed: 05/31/2012
• Published: 12/05/2013
• Est. Priority Date: 05/31/2012
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Cote, Guy, Lin, Sheng, Lim, Suk Hwan, Silverstein, D. Amnon, Butler, Simon Wolfenden, Zimmer, Mark A., Bratt, Joseph P.
• Granted Patent: US 9,025,867 B2
• Time in Patent Office: Days
• US Class Current: 382/163
• CPC Class Codes: G06T 1/20 Processor architectures; Processor configuration, e.g. pipelining
• CPC Class Codes: G06T 3/4015 Image demosaicing, e.g. colour filter arrays [CFA] or Bayer patterns

Abstract

Systems and methods for processing YCC image data provided. In one example, an electronic device includes memory to store image data in RGB or YCC format and a YCC image processing pipeline to process the image data. The YCC image processing pipeline may include receiving logic configured to receive the image data in RGB or YCC format and color space conversion logic configured to, when the image data is received in RGB format, convert the image data into YCC format. The YCC image processing logic may also include luma sharpening and chroma suppression logic; brightness, contrast, and color adjustment logic; gamma logic; chroma decimation logic; scaling logic; and chromanoise reduction logic.

Claims

1. An electronic device comprising:

memory configured to store image data in RGB or YCC format, or both, wherein the YCC format comprises one luminance component and two chrominance components;

a YCC image processing pipeline configured to process the image data, wherein the YCC image processing pipeline comprises;

receiving logic configured to receive the image data in RGB or YCC format;

color space conversion logic configured to, when the image data is received in RGB format, convert the image data into YCC format;

luma sharpening and chroma suppression logic to generally sharpen the luminance component of the image data and generally suppress noise in the chrominance components of the image data;

brightness, contrast, and color adjustment logic to adjust brightness, contrast, or color, or a combination thereof, of the image data;

gamma logic adjust a gamma of the image data;

chroma decimation logic to decimate the chrominance components of the image data;

scaling logic configured to scale the image data; and

chromanoise reduction logic configured to reduce noise in the chrominance components of the image data.

2. The electronic device of claim 1, wherein the logic of the YCC image processing pipeline is configured to process the image data in the recited order.

3. The electronic device of claim 1, wherein the color space conversion is configured to operate on signed image data.

4. The electronic device of claim 1, wherein the YCC image processing pipeline is configured to process the image data in overlapping tiles of a larger image frame.

5. The electronic device of claim 1, wherein the RGB image processing logic is configured to receive at least the following formats:

RGB565, RGB888, RGB16, YCC16 4;

4;

4 (1-plane), 10-bit YCC 4;

2;

2 (1-plane or 2-plane), and 8-bit YCC 4;

2;

2 (1-plane or 2-plane).

6. The electronic device of claim 5, comprising data conversion logic configured to convert the received image data into signed image data of a common bit depth before it is processed by the YCC processing pipeline.

7. The electronic device of claim 1, wherein the YCC image processing logic is configured to output processed YCC image data and reprocess the processed YCC image data.

8. The electronic device of claim 1, wherein the YCC image processing logic is configured to output at least the following formats:

8-bit YCC 4;

2;

2 (1-plane), 10-bit YCC 4;

2;

2 (1-plane), 8-bit YCC 4;

2;

2 (2-plane), 10-bit YCC 4;

2;

2 (2-plane), 8-bit YCC 4;

2;

0 (2-plane), and 10-bit YCC 4;

2;

0 (2-plane).

9. The electronic device of claim 1, wherein the YCC comprising selection logic to programmably vary a processing order of the scaling logic and the chromanoise reduction logic.

10. The electronic device of claim 1, comprising an RGB image processing pipeline configured to perform RGB processing on the image data before providing the processed image data to the memory or to the YCC image processing pipeline.

11. The electronic device of claim 1, comprising an imaging device, wherein the imaging device comprises a digital camera integrated with the electronic device, an external digital camera coupled to the electronic device via an input/output port, or some combination thereof.

12. The electronic device of claim 1, comprising at least one of a desktop computer, a laptop computer, a tablet computer, a mobile cellular telephone, a portable media player, or any combination thereof.

13. An electronic device comprising:

memory configured to store image data; and

an image signal processor comprising;

pre-YCC image processing logic configured to perform a plurality of image processing operations on the image data in raw format or RGB format, or both raw and RGB format; and

a YCC image processing pipeline configured to perform a plurality of image processing operations on the image data in YCC format, wherein the YCC image processing pipeline comprises selection logic to receive the image data from the memory or from the pre-YCC image processing logic.

14. The electronic device of claim 13, wherein the YCC image processing pipeline is configured to output processed YCC image data in a plurality of resolutions.

15. The electronic device of claim 13, comprising an imaging device to obtain the image data, wherein the imaging device comprises a lens that produces geometric distortion in the image data, and wherein the YCC image processing pipeline comprises geometric distortion logic configured to correct for the geometric distortion in the image data.

16. The electronic device of claim 15, wherein the geometric distortion logic comprises a component of scaling logic configured both to scale the image data and correct for the geometric distortion in the image data.

17. The electronic device of claim 13, wherein the YCC image processing pipeline comprises horizontal decimation logic configured to horizontally decimate chroma components of the image data after filtering the chroma components in a lancsoz filter.

18. The electronic device of claim 13, wherein the YCC image processing pipeline comprises horizontal decimation logic comprising a plurality of filter modes to filter chroma components of the image data before horizontally decimating the chroma components.

19. The electronic device of claim 18, wherein the filter modes comprise a Gaussian filter mode and a lancsoz filter mode.

20. An image signal processing system comprising:

a YCC processing pipeline configured to operate on image data in YCC format, wherein the image data in YCC format comprises a luminance component, a first chrominance component, and a second chrominance component, wherein the YCC processing pipeline comprises brightness, contrast, and color adjustment logic configured to control saturation in the chrominance components of the image data based at least in part on both saturation and hue of the image data.

21. The image signal processing system of claim 20, wherein the brightness, contrast, and color logic comprises a two-dimensional lookup table indexed to both the first chrominance component and the second chrominance component to obtain adjusted values for the first chrominance component and the second chrominance component.

22. The image signal processing system of claim 21, wherein the adjusted values are obtained through linear interpolation of the four closest points in a space defined by the first chrominance component and the second chrominance component.

23. The image signal processing system of claim 21, wherein the two-dimensional lookup table is configured to apply adjustments more flattering to skin tones when the first chrominance component and the second chrominance component indexed to the table are typically associated with skin tones.

24. A method for processing image data, comprising:

receiving image data of RGB or YCC format into a pipeline of an image signal processor, wherein the YCC format comprises a luma component and two chroma components;

when the image data is of RGB format, converting the image data into YCC format image data using color space conversion logic;

performing luma sharpening and chroma suppression on the image data;

applying a brightness, contrast, and color adjustment to the image data;

horizontally decimating the chroma components of the image data; and

scaling the image data.

25. The method of claim 24, wherein the method is performed in the recited order.

26. The method of claim 25, comprising performing gamma mapping on the image data after the brightness, contrast, and color adjustment is applied to the image data and before the two chroma components are horizontally decimated.

27. The method of claim 24, wherein horizontally decimating the chroma components comprises applying a lancsoz filter to the two chroma components.

28. The method of claim 24, wherein applying the brightness, contrast, and color adjustment to the image data comprises adjusting the two chroma components using a two-dimensional lookup table indexed to both chroma components.

29. The method of claim 24, wherein applying the brightness, contrast, and color adjustment to the image data comprises adjusting the two chroma components using a spatially varying lookup table indexed to both chroma components.

30. The method of claim 24, wherein scaling the image data comprises scaling the image data into two resolutions.

31. The method of claim 24, wherein scaling the image data comprises correcting for geometric distortion in the image data.