Resampling chroma video using a programmable graphics processing unit to provide improved color rendering
View Patent ↗A system which utilizes the processing capabilities of the graphics processing unit (GPU) in the graphics controller. Each frame of each video stream is decoded. After decoding the compressed image is separated into an image representing the luminance and an image representing the chroma. The chroma image is resampled as appropriate using the GPU to provide chroma values corresponding to each luminance value at the proper locations. The resampled chroma image and the luminance image are properly combined to produce a 4:4:4 image, preferably in the RGB color space, and provided to the frame buffer for final display. Each of these operations is done in real time for each frame of the video.
1. A method for displaying digital video, comprising:
decoding compressed digital video information having subsampled chroma values;
separating the decoded video information into original luminance values and original chroma values;
resampling the original chroma values to provide resampled chroma values for each original luminance value;
providing the original luminance values to a first buffer as a first grayscale image;
providing the resampled chroma values to a second buffer as a second grayscale image with opacity information, with one chroma value placed in the luminance portion of the second grayscale image and the other chroma value placed in the opacity portion of the second grayscale image; and
combining the original luminance values in the first grayscale image and the resampled chroma values in the second grayscale image into a buffer for display.
2. The method of claim 1 , wherein the resampling is performed using a linear function.
3. The method of claim 1 , wherein the resampling is performed using a sinc function.
4. The method of claim 1 , wherein the resampling of the decoded chroma values compensates for the location of the decoded chroma values in relation to the luminance values.
5. The method of claim 1 , wherein the resampling is performed in a graphics processing unit.
6. A computer readable storage device or devices having computer-executable instructions stored therein for performing the following method for displaying digital video, the method comprising:
decoding compressed digital video information having subsampled chroma values;
separating the decoded video information into original luminance values and original chroma values;
resampling the original chroma values to provide resampled chroma values for each original luminance value;
providing the original luminance values to a first buffer as a first grayscale image;
providing the resampled chroma values to a second buffer as a second grayscale image with opacity information, with one chroma value placed in the luminance portion of the second grayscale image and the other chroma value placed in the opacity portion of the second grayscale image; and
combining the original luminance values in the first grayscale image and the resampled chroma values in the second grayscale image into a buffer for display.
7. The computer readable storage device or devices of claim 6 , wherein the resampling is performed using a linear function.
8. The computer readable storage device or devices of claim 6 , wherein the resampling is performed using a sinc function.
9. The computer readable storage device or devices of claim 6 , wherein the resampling of the decoded chroma values compensates for the location of the decoded chroma values in relation to the luminance values.
10. The computer readable storage device or devices of claim 6 , wherein the resampling is performed in a graphics processing unit.
11. A computer system comprising:
a central processing unit;
memory, operatively coupled to the central processing unit, said memory adapted to provide a plurality of buffers, including a frame buffer;
a display port operatively coupled to the frame buffer and adapted to couple to a display device;
a graphics processing unit, operatively coupled to the memory; and
one or more programs for causing the central processing unit or graphics processing unit to perform the following method, the method including: decoding compressed digital video information having subsampled chroma values;
separating the decoded video information into original luminance values and original chroma values;
resampling the original chroma values to provide resampled chroma values for each original luminance value;
providing the original luminance values to a first buffer as a first grayscale image;
providing the resampled chroma values to a second buffer as a second grayscale image with opacity information, with one chroma value placed in the luminance portion of the second grayscale image and the other chroma value placed in the opacity portion of the second grayscale image; and
combining the original luminance values in the first grayscale image and the resampled chroma values in the second grayscale image into a buffer for display,
wherein the luminance values are provided to the first buffer as a grayscale image and wherein the chroma values are provided to the second buffer as a grayscale image with opacity information, with one chroma value in the luminance portion and the other chroma value in the opacity portion.
12. The computer system of claim 11 , wherein the resampling is performed using a linear function.
13. The computer system of claim 11 , wherein the resampling is performed using a sinc function.
14. The computer system of claim 11 , wherein the resampling of the decoded chroma values compensates for the location of the decoded chroma values in relation to the luminance values.