IMAGE FORMATS FOR VIDEO CAPTURE, PROCESSING AND DISPLAY

• US 20070296861A1
• Filed: 09/06/2007
• Published: 12/27/2007
• Est. Priority Date: 03/10/2004
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Estrop, Stephen, Evans, Glenn
• Granted Patent: US 7,548,245 B2
• Time in Patent Office: Days
• US Class Current: 348/488
• CPC Class Codes: H04N 19/186 the unit being a colour or a chrominance component
• CPC Class Codes: H04N 19/423 characterised by memory arrangements H04N19/433 takes precedence
• CPC Class Codes: H04N 19/61 in combination with predictive coding

Abstract

Techniques and tools for representing pixel data in a video processing or capture system are described. Described techniques and tools provide efficient color representation for video processing and capture, and provide flexibility for representing colors using different bit precisions and memory layouts. Described techniques and tools include video formats that can be used, for example, in hardware or software for capture, processing, and display purposes. In one aspect, chroma and luma information for a pixel in a video image is represented in a 16-bit fixed-point block of data having an integer and fractional components. Data can be easily converted from one representation to another (e.g., between 16-bit and 10-bit representations). In other aspects, formats for representing 8-, 10- and 16-bit video image data (e.g., packed and hybrid planar formats), and codes for indicating the formats, are described.

Claims

1. A computer-readable medium having stored thereon a four-character code for digital video data, the four-character code operable to indicate a format of the digital video data in a computer system, the four-character code comprising:

a first character based on whether the format is a packed format or a hybrid planar format;

a second character based on chroma sampling in the format; and

third and fourth characters based on a bit precision of the format.

2. The computer-readable medium of claim 1 wherein the four-character code is included in a file header of a file containing the digital video data.

3. The computer-readable medium of claim 2 wherein the four-character code is changeable to cast the format of the digital video data to a different bit precision.

4. In a computer system, a method of representing video data for a video image, the method comprising:

representing the video data in a hybrid planar format representation, the hybrid planar format representation having a bit precision of greater than eight bits per channel, the hybrid planar format representation having a first array comprising luma information for pixels in the video image and a second array comprising chroma information for the pixels in the video image, and where the chroma information is stored within the second array in a packed format.

5. The method of claim 4 wherein the video data is in a 4:

2;

2 sub-sampling format.

6. The method of claim 4 wherein the video data is in a 4:

2;

0 sub-sampling format.

7. The method of claim 4 wherein the video data is in a 4:

1;

1 sub-sampling format.

8. The method of claim 4 wherein the chroma information is stored as interleaved pairs of chroma components.

9. A computer-readable medium having computer-executable instructions stored thereon for performing the method of claim 4.

10. In a computer system, a method of representing video data for a video image, the method comprising:

representing video data in a hybrid planar format representation, the hybrid planar format representation having a bit precision of greater than or equal to eight bits per channel, where the hybrid planar format representation includes a first array comprising luma information for pixels in the video image and a second array comprising chroma information for the pixels in the video image, where the chroma information is stored within the second array in a packed format, and where the chroma information is sub-sampled in the horizontal direction by a factor of two.

11. The method of claim 10 wherein the video data is in a 4:

2;

2 sub-sampling format.

12. In a computer system, a method of representing video data for a video image, the method comprising:

representing chroma and luma information for a pixel in the video image in an n-bit representation, the n-bit representation comprising a 16-bit fixed-point block of data for the pixel, where the most significant byte in the 16-bit unit of data is an integer component, where the least significant byte in the 16-bit unit of data is a fractional component, and where the n-bit representation is convertible to a higher-precision representation by changing an identifier for the video data.

13. The method of claim 12 wherein the identifier is a FOURCC code.

14. The method of claim 12 wherein the n-bit representation is a 10-bit representation and the higher-precision representation is a 16-bit representation.

15. The method of claim 12 wherein the chroma information is sampled at a resolution less than the luma information.

16. A computer-readable medium having computer-executable instructions stored thereon for performing the method of claim 12.