System and method for three dimensional comb filtering

1. A method for indicating whether to process a current signal using three-dimensional comb filtering, the method comprising:

performing by at least one circuit:

analyzing an inter-frame luma signal to determine whether to process a current signal using three-dimensional comb filtering or whether to perform additional analysis;

if, based on the analysis of the inter-frame luma signal, it is determined to perform additional analysis, then analyzing an intra-frame luma signal to determine whether processing the current signal using three-dimensional comb filtering is appropriate; and

generating a signal indicating whether processing the current signal using three-dimensional comb filtering is appropriate.

2. The method of claim 1 , wherein analyzing an inter-frame luma signal to determine whether to process a current signal using three-dimensional comb filtering or whether to perform additional analysis comprises:

generating a filtered inter-frame luma signal by, at least in part, substantially removing at least one frequency component from the inter-frame luma signal; and

determining whether to process the current signal using three-dimensional comb filtering based, at least in part, on the filtered inter-frame luma signal.

3. The method of claim 2 , wherein generating a filtered inter-fame luma signal comprises substantially removing frequency components from the inter-frame luma signal that are not within at least one portion of the chroma frequency band.

4. The method of claim 1 , wherein analyzing an intra-frame luma signal to determine whether processing the current signal using three-dimensional comb filtering is appropriate comprises determining whether processing the current signal using three-dimensional comb filtering is appropriate based, at least in part, on frequency content of the intra-frame luma signal.

5. The method of claim 4 , wherein determining whether processing the current signal using three-dimensional comb filtering is appropriate based, at least in part, on frequency content of the intra-frame luma signal comprises:

generating a filtered intra-frame luma signal by, at least in part, substantially removing at least one frequency component from the intra-frame luma signal; and

determining whether processing the current signal using three-dimensional comb filtering is appropriate based, at least in part, on the filtered intra-frame luma signal.

6. A method for indicating whether to process a current signal using three-dimensional comb filtering, the method comprising:

performing by at least one circuit:

generating an inter-frame chroma signal;

determining, based at least in part on the inter-frame chroma signal and a plurality of different thresholds, whether to process a current signal using three-dimensional comb filtering; and

if it is determined that processing the current signal using three-dimensional comb filtering is appropriate, then generating a signal indicating that three-dimensional comb filtering the current signal is appropriate.

7. The method of claim 6 , wherein determining whether to process the current signal using three-dimensional filtering comprises:

generating a filtered inter-frame chroma signal by, at least in part, filtering the inter-frame chroma signal;

comparing a magnitude of the filtered inter-frame chroma signal to a first threshold;

comparing a magnitude of the filtered inter-frame chroma signal to a second threshold, the second threshold different from the first threshold; and

determining whether to process the current signal using three-dimensional comb filtering based, at least in part, on the comparison between a magnitude of the filtered inter-frame chroma signal and the first threshold and the comparison between a magnitude of the filtered inter-frame chroma signal and second threshold.

8. The method of claim 7 , wherein the second threshold is less than the first threshold, and further comprising:

determining not to process the current signal using three-dimensional comb filtering if a magnitude of the filtered inter-frame chroma signal is greater than the first threshold; and

determining to process the current signal using three-dimensional comb filtering if a magnitude of the filtered inter-frame chroma signal is less than the second threshold.

9. The method of claim 7 , wherein generating a filtered inter-frame chroma signal comprises substantially removing frequency components from the inter-frame chroma signal that correspond generally to the chroma frequency band.

10. The method of claim 6 , wherein determining, based at least in part on the inter-frame chroma signal and a plurality of different thresholds, whether to process a current signal using three-dimensional comb filtering comprises:

generating an inter-frame luma signal; and

determining, based at least in part on the inter-frame luma signal, whether to process the current signal using three-dimensional comb filtering.

11. A system for indicating whether to process a current signal using three-dimensional comb filtering, the system comprising:

at least one circuit that is operable to, at least:

analyze an inter-frame luma signal to determine whether to process a current signal using three-dimensional comb filtering or whether to perform additional analysis;

if, based on the analysis of the inter-frame luma signal, it is determined to perform additional analysis, then analyze an intra-frame luma signal to determine whether processing the current signal using three-dimensional comb filtering, is appropriate; and

generate a signal indicating whether processing the current signal using three-dimensional comb filtering is appropriate.

12. The system of claim 11 , wherein to analyze an inter-frame luma signal to determine whether to process a current signal using three-dimensional comb filtering or whether to perform additional analysis, the at least one circuit is operable to, at least in part:

generate a filtered inter-frame luma signal by, at least in part, substantially removing at least one frequency component from the inter-frame luma signal; and

determine whether to process the current signal using three-dimensional comb filtering based, at least in part, on the magnitude of the filtered inter-frame luma signal.

13. The system of claim 12 , wherein to generate a filtered inter-fame luma signal, the at least one circuit is operable to, at least in part, substantially remove frequency components from the inter-frame luma signal that are not within at least one portion of the chroma frequency band.

14. The system of claim 11 , wherein to analyze an intra-frame luma signal to determine whether processing the current signal using three-dimensional comb filtering is appropriate, the at least one circuit is operable to, at least in part, determine whether processing the current signal using three-dimensional comb filtering is appropriate based, at least in part, on frequency content of the intra-frame luma signal.

15. The system of claim 14 , wherein to determine whether processing the current signal using three-dimensional comb filtering is appropriate based, at least in part, on frequency content of the intra-frame luma signal, the at least one circuit is operable to, at least in part:

generate a filtered intra-frame luma signal by, at least in part, substantially removing at least one frequency component from the intra-frame luma signal; and

determine whether processing the current signal using three-dimensional comb filtering is appropriate based, at least in part, on the magnitude of the filtered intra-frame luma signal.

16. A system for indicating whether to process a current signal using three-dimensional comb filtering, the system comprising:

at least one circuit that is operable to, at least:

generate an inter-frame chroma signal;

determine, based at least in part on the inter-frame chroma signal and a plurality of different thresholds, whether to process a current signal using three-dimensional comb filtering; and

if it is determined that processing the current signal using three-dimensional comb filtering is appropriate, then generate a signal indicating that three-dimensional comb filtering the current signal is appropriate.

17. The system of claim 16 , wherein to determine whether to process the current signal using three-dimensional filtering, the at least one circuit is operable to, at least in part:

generate a filtered inter-frame chroma signal by, at least in part, filtering the inter-frame chroma signal;

compare a magnitude of the filtered inter-frame chroma signal to a first threshold;

compare a magnitude of the filtered inter-frame chroma signal to a second threshold, the second threshold different from the first threshold; and

determine whether to process the current signal using three-dimensional comb filtering based, at least in part, on the comparison between a magnitude of the filtered inter-frame chroma signal and the first threshold and the comparison between a magnitude of the filtered inter-frame chroma signal and second threshold.

18. The system of claim 17 , wherein the second threshold is less than the first threshold, and the at least one circuit is operable to, at least:

determine not to process the current signal using three-dimensional comb filtering if a magnitude of the filtered inter-frame chroma signal is greater than the first threshold; and

determine to process the current signal using three-dimensional comb filtering if a magnitude of the filtered inter-frame chroma signal is less than the second threshold.

19. The system, of claim 17 , wherein to generate a filtered inter-frame chroma signal, the at least one circuit is operable to, at least in part, substantially remove frequency components from the inter-frame chroma signal that correspond generally to the chroma frequency band.

20. The system of claim 16 , wherein to determine, based at least in part on the inter-frame chroma signal and a plurality of different thresholds, whether to process a current signal using three-dimensional comb filtering, the at least one circuit is operable to, at least in part:

generate an inter-frame luma signal; and

determine, based at least in part on the inter-frame luma signal, whether to process the current signal using three-dimensional comb filtering.