System and method for video quality parametric tests
A method for measuring the amount of noise in a video image includes receiving a signal from an imaging device; extracting a luma component from a color image; applying a filter to compute the second derivatives of the extracted luma component; determining a ratio of noise pixels to total pixels in the second derivative; and comparing the ratio to a pre-determined ratio.
1. A method for measuring the amount of noise in a video image, the method comprising:
receiving a signal from an imaging device;
extracting a luma component from a color image from the imaging device;
applying a filter to compute the second derivatives of the extracted luma component;
determining a ratio of noise pixels to total pixels in the second derivative; and
comparing the ratio to a pre-determined ratio.
2. The method of claim 1 , wherein the filter is a Laplace filter.
3. The method of claim 1 , wherein pixels are binarized prior to determining the ratio of noise pixels to total pixels.
4. The method of claim 1 , wherein the signal comprises smooth areas in the background of the images.
5. The method of claim 1 , wherein the signal comprises a color bar pattern.
6. The method of claim 1 , wherein if the ratio exceeds the pre-determined ratio the signal is rejected.
7. The method of claim 1 , wherein if the ratio is less than the pre-determined ratio the signal is accepted.
8. The method of claim 1 , wherein if the ratio exceeds the pre-determined ratio, the imaging device is determined to be faulty.
9. An apparatus for determining the functioning of an imaging device comprising;
a processor;
memory, coupled to the processor, wherein the memory is configured to allow the processor to:
obtain a video signal;
extract a luma component from the video signal;
filter the luma component to determine a ratio of noise pixels to total pixels in a second derivative of the extracted luma component;
compare the ratio of noise pixels to total pixels to a pre-determined ratio; and
wherein if the processor determines that the ratio of noise pixels to total pixels exceeds the pre-determined ratio, the processor emits an error code indicating that the imaging device is non-functioning.
10. The apparatus of claim 9 , wherein the filter is a Laplace filter.
11. The apparatus of claim 9 , wherein the filter is an omnidirectional filter.
12. The apparatus of claim 9 , wherein the filter recognizes small changes in contrast around pixels.
13. The apparatus of claim 9 , wherein the luma component is the Y signal of a color image.
14. A system for video quality assessment comprising:
a video imaging device;
a testing device for measuring the amount of noise in a video image from the video imaging device;
wherein the testing device comprises logic that enables determination of the amount of noise in a video picture by evaluating the contrast between neighboring pixels and calculating the ratio of noisy pixels to total pixels in a second derivative of extracted luma components of the video image.
15. The system of claim 14 , wherein the contrast between neighboring pixels is determined by applying a Laplace filter.
16. The system of claim 14 , wherein the contrast between neighboring pixels is determined by applying an omnidirectional filter.
17. The system of claim 14 , wherein the video imaging device sends a signal to the testing device.
18. The system of claim 14 , wherein the contrast between pixels is determined in a Y signal.
19. The system of claim 14 , comprising logic to control an RF attenuation of a video image signal to induce noise in the video imaging device.