System and method of reducing distortion during downsampling
A video processing system is provided for reducing distortion in video signals. The system includes a first transfer function that applies a transfer function to a received video signal to generate a gamma corrected video signal in a first color space; and a first matrix component that transforms the gamma corrected video signal in the first color space to a gamma corrected signal in a second color space, and extracts a luminance component from the gamma corrected signal in the second color space. Moreover, the system includes a second transfer function that generates a gamma corrected downsampled video signal in the first color space, and a second matrix component that transforms the gamma corrected video signal in the first color space to a gamma corrected video signal in the second color space, and extracts the chroma component in the second color space.
1. A video processing system for reducing distortion in video signals, the video processing system comprising:
a low-pass filter configured to down sample a video signal in a first color space to generate a down-sampled video signal in the first color space;
a first transfer function configured to generate a gamma corrected video signal in the first color space from the video signal;
a second transfer function configured to generate a gamma corrected down-sampled video signal in the first color space from the generated down-sampled video signal;
at least one matrix component configured to generate a gamma corrected video signal in a second color space from the gamma corrected video signal in the first color space, and to generate a gamma corrected down-sampled video signal in the second color space from the gamma corrected down-sampled video signal; and
an output configured to transmit at least one of the gamma corrected video signal in the second color space and the gamma corrected down-sampled video signal in the second color space to a display device to be displayed thereon.
2. The video processing system according to claim 1 , further comprising:
a video signal splitter configured to split the video signal to a first split signal and a second split signal,
wherein the first transfer function applies a transfer function to the first split signal to generate the gamma corrected video signal in the first color space, and
wherein the low-pass filter down samples the second split signal as the video signal in the first color space to generate the down-sampled video signal in the first color space.
3. The video processing system according to claim 2 , wherein the at least one matrix is configured to extract a luminance component from the gamma corrected video signal in the second color space, and to extract a chroma component of the gamma corrected down-sampled video signal in the second color space.
4. The video processing system according to claim 3 , wherein the video signal is an RGB video signal in the first color space and the first and second split signals are identical signals for the RGB video signal.
5. The video processing system according to claim 4 , wherein the first transfer function is configured to apply a non-linear transformation to the RGB video signal to generate an R′G′B′ gamma corrected video signal.
6. The video processing system according to claim 5 , wherein the at least one matrix component is configured to:
apply a matrix transform to the R′G′B′ gamma corrected video signal to extract a Y′ (luma) component as the luminance component; and
transform the RGB video signal in the first color space to a CBCR signal.
7. The video processing system according to claim 4 , wherein the video signal splitter comprises a third matrix component configured to transform respective linear RGB components of the RGB video signal to linear LMS components that are split to provide the first and second split signals.
8. The video processing system according to claim 1 , further comprising electronic memory and a processor configured to execute instructions stored on the electronic memory for providing the first transfer function to generate the gamma corrected video signal in the first color space from the video signal, the second transfer function to generate the gamma corrected down-sampled video signal in the first color space, and the at least one matrix component to generate the gamma corrected video signal in the second color space and the gamma corrected down-sampled video signal in the second color space.
9. A video processing system for reducing distortion in video signals, the video processing system comprising:
a filter configured to down sample a video signal in a first color space to generate a down-sampled video signal in the first color space;
a first transfer function configured to transform the video signal to a gamma corrected video signal in the first color space;
a second transfer function configured to transform the generated down-sampled video signal to a gamma corrected down-sampled video signal in the first color space; and
at least one matrix component configured to generate a gamma corrected video signal in a second color space from the gamma corrected video signal in the first color space, and to generate a gamma corrected down-sampled video signal in the second color space from the gamma corrected down-sampled video signal.
10. The video processing system according to claim 9 , further comprising a multiplexer configured to transmit at least one of the gamma corrected video signal in the second color space and the gamma corrected down-sampled video signal in the second color space to a display device to be displayed thereon.
11. The video processing system according to claim 9 , further comprising:
a video signal splitter configured to split the video signal to a first split signal and a second split signal,
wherein the first transfer function applies a transfer function to the first split signal to generate the gamma corrected video signal in the first color space, and
wherein the filter down samples the second split signal as the video signal in the first color space to generate the down-sampled video signal in the first color space.
12. The video processing system according to claim 11 , wherein the at least one matrix is configured to extract a luminance component from the gamma corrected video signal in the second color space, and to extract a chroma component of the gamma corrected down-sampled video signal in the second color space.
13. The video processing system according to claim 12 , wherein the video signal is an RGB video signal in the first color space and the first and second split signals are identical signals for the RGB video signal.
14. The video processing system according to claim 13 , wherein the first transfer function is configured to apply a non-linear transformation to the RGB video signal to generate an R′G′B′ gamma corrected video signal.
15. The video processing system according to claim 14 , wherein the at least one matrix component is configured to:
apply a matrix transform to the R′G′B′ gamma corrected video signal to extract a Y′ (luma) component as the luminance component; and
transform the RGB video signal in the first color space to a CBCR signal.
16. The video processing system according to claim 13 , wherein the video signal splitter comprises a third matrix component configured to transform respective linear RGB components of the RGB video signal to linear LMS components that are split to provide the first and second split signals.
17. The video processing system according to claim 9 , further comprising electronic memory and a processor configured to execute instructions stored on the electronic memory for providing the first transfer function to generate the gamma corrected video signal in the first color space from the video signal, the second transfer function to generate the gamma corrected down-sampled video signal in the first color space, and the at least one matrix component to generate the gamma corrected video signal in the second color space and the gamma corrected down-sampled video signal in the second color space.
18. A video processing system for reducing distortion in video signals, the video processing system comprising:
means for down sampling a video signal in a first color space to generate a down-sampled video signal in the first color space;
means for transforming the video signal to a gamma corrected video signal in the first color space;
means for transforming the generated down-sampled video signal to a gamma corrected down-sampled video signal in the first color space;
means for generating a gamma corrected video signal in a second color space from the gamma corrected video signal in the first color space; and
means for generating a gamma corrected down-sampled video signal in the second color space from the gamma corrected down-sampled video signal.
19. The video processing system according to claim 18 , further comprising means for transmitting at least one of the gamma corrected video signal in the second color space and the gamma corrected down-sampled video signal in the second color space to a display device to be displayed thereon.
20. The video processing system according to claim 19 , further comprising:
means for extracting a luminance component from the gamma corrected video signal in the second color space; and
means for extracting a chroma component of the gamma corrected down-sampled video signal in the second color space.