ADAPTIVE PROCESSING OF VIDEO STREAMS WITH REDUCED COLOR RESOLUTION

• US 20150245042A1
• Filed: 02/19/2015
• Published: 08/27/2015
• Est. Priority Date: 02/21/2014
• Status: Active Grant

• Current Assignee: Lattice Semiconductor Corporation
• Original Assignee: Silicon Image, Inc. (Lattice Semiconductor Corporation)
• Inventors: Thompson, Laurence Alan
• Granted Patent: US 9,699,469 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04N 19/136 Incoming video signal characteristics or properties
• CPC Class Codes: H04N 19/172 the region being a picture, frame or field
• CPC Class Codes: H04N 19/186 the unit being a colour or a chrominance component
• CPC Class Codes: H04N 19/196 being specially adapted for the computation of encoding parameters, e.g. by averaging previously computed encoding parameters processing of motion vectors H04N19/513
• CPC Class Codes: H04N 19/85 using pre-processing or post-processing specially adapted for video compression

Abstract

A solution for adaptively processing a digital image with reduced color resolution is described herein. A source device pre-processes a video frame with reduce color resolution by remapping luma components and chroma components of the video frame, and encodes the pre-processed video frame. The source device remaps a half of luma components on a scan line of the video frame onto a data channel of a source line to an encoder and remaps the other half of the luma components on the scan line to another data channel of the source line. The source device remaps the corresponding chroma components onto a third data channel of a source line. By using a data channel conventionally configured to transmit chroma components, the solution enables a video codec to adaptively encode a digital image with reduced color resolution without converting the digital image to full color resolution before the encoding.

Claims

1. A method for encoding a digital image, the method comprising:

receiving the digital image of a plurality of pixels, each pixel having a luma component and two chroma components;

extracting luma components and chroma components from the plurality of pixels;

reordering the luma components and reordering the chroma components; and

generating a data structure representing the digital image based on the reordering of the luma components and the reordering of the chroma components.

2. The method of claim 1, further comprising encoding the digital image according to the data structure.

3. The method of claim 1, wherein each of the plurality of pixels is in a sampling format, where two chroma components of the pixel are sampled at half the sample rate of luma component of the pixel in horizontal and vertical directions.

4. The method of claim 1, wherein the plurality of pixels of the digital image are received in an order according to a scan line of the plurality of pixels, each scan lining having a predetermined horizontal resolution.

5. The method of claim 1, wherein the reordering the luma components comprises:

for a plurality of pixels received on a scan line;

separating the luma components of the pixels on the scan line into two parts, wherein each part has a half of the luma components of the plurality of pixels on the scan line;

selecting two data channels among three data channels configured for transmitting the luma components and chroma components of the pixels on the scan line;

providing the first part of the luma components on one of the selected data channels; and

providing the second part of the luma components on the other selected data channels.

6. The method of claim 1, wherein the digital image is partitioned into a plurality of subpictures, each subpicture having a partial horizontal resolution of a corresponding horizontal resolution of the digital picture, and each subpicture having a partial vertical resolution of a corresponding vertical resolution of the digital picture.

7. The method of claim 1, further comprising maintaining a spatial relationship of each pixel component within a subpicture after reordering such that the spatial relationship of individual pixel components within the subpicture is the same as the spatial relationship of the corresponding individual components within the subpicture.

8. A method for decoding an encoded digital image, the method comprising:

receiving the encoded digital image of a plurality of pixels, each pixel having a luma component and two chroma components;

extracting luma components and chroma components from the plurality of pixels;

reordering the luma components and reordering the chroma components according a data structure describing the reordering; and

reconstructing a digital image with reduced color resolution based on the reordering of the luma components and the chroma components of the digital image.

9. The method of claim 8, wherein the reordering the luma components comprises:

selecting the luma components of the pixels on two data channels, wherein each data channel has a half of the luma components of the plurality of pixels on a scan line; and

reordering the selected luma components on the scan line according to the data structure describing the reordering.

10. A non-transitory computer readable medium storing executable computer program instructions for encoding a digital image, the computer program instructions comprising instructions that when executed cause a computer processor to:

receive the digital image of a plurality of pixels, each pixel having a luma component and two chroma components;

extract luma components and chroma components from the plurality of pixels;

reorder the luma components and reorder the chroma components; and

generate a data structure representing the digital image based on the reordering of the luma components and the reordering of the chroma components.

11. The computer readable medium of claim 10, further comprising computer program instructions that when executed cause the computer processor to encode the digital image according to the data structure.

12. The computer readable medium of claim 10, wherein each of the plurality of pixels is in a sampling format, where two chroma components of the pixel are sampled at half the sample rate of luma component of the pixel in horizontal and vertical directions.

13. The computer readable medium of claim 10, wherein the plurality of pixels of the digital image are received in an order according to a scan line of the plurality of pixels, each scan lining having a predetermined horizontal resolution.

14. The computer readable medium of claim 10, wherein the computer program instructions for reordering the luma components comprise instructions that when executed cause the computer processor to:

for a plurality of pixels received on a scan line;

separate the luma components of the pixels on the scan line into two parts, wherein each part has a half of the luma components of the plurality of pixels on the scan line;

select two data channels among three data channels configured for transmitting the luma components and chroma components of the pixels on the scan line;

provide the first part of the luma components on one of the selected data channels; and

provide the second part of the luma components on the other selected data channels.

15. The computer readable medium of claim of claim 10, wherein the digital image is partitioned into a plurality of subpictures, each subpicture having a partial horizontal resolution of a corresponding horizontal resolution of the digital picture, and each subpicture having a partial vertical resolution of a corresponding vertical resolution of the digital picture.

16. The computer readable medium of claim 10, further comprising computer program instructions to maintain a spatial relationship of each pixel component within a subpicture after reordering such that the spatial relationship of individual pixel components within the subpicture is the same as the spatial relationship of the corresponding individual components within the subpicture.

17. A non-transitory computer readable medium storing executable computer program instructions for decoding an encoded digital image, the computer program instructions comprising instructions that when executed cause a computer processor to:

receive the encoded digital image of a plurality of pixels, each pixel having a luma component and two chroma components;

extract luma components and chroma components from the plurality of pixels;

reorder the luma components and reorder the chroma components according a data structure describing the reordering; and

reconstruct a digital image with reduced color resolution based on the reordering of the luma components and the chroma components of the digital image.

18. The computer readable medium of claim 17, wherein the computer program instructions for reordering the luma components comprise instructions that when executed cause computer processor to:

select the luma components of the pixels on two data channels, wherein each data channel has a half of the luma components of the plurality of pixels on a scan line; and

reorder the selected luma components on the scan line according to the data structure describing the reordering.