Patent ID: 7227587

Claim:
A method for indicating whether to process a current signal using three-dimensional comb filtering, the current signal corresponding to a signal in a current video line of a current video field of a current video frame, the current signal having a luma component, a chroma component, a chroma frequency band and a chroma sub-carrier frequency, the method comprising: generating an inter-frame luma signal; generating a filtered inter-frame luma signal by signal processing, comprising substantially removing at least one frequency component from the inter-frame luma signal; and if the magnitude of the filtered inter-frame luma signal is less than a first threshold, then generating a signal indicating that three-dimensional comb filtering the current signal is appropriate; and if the magnitude of the filtered inter-frame luma signal is not less than the first threshold, then: generating a first intra-frame luma signal; determining, based on at least the frequency content of the first intra-frame luma signal, 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.