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Whats the purpose of.....

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Old 04-07-2002, 8:18 PM   #1
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Whats the purpose of.....

Whats the purpose of a 'comb filter'? Can someone please explain. Is it a permanently switch on feature or can it be turned off / on? I have a sony 32fq75. thanks.
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Old 04-07-2002, 9:06 PM   #2
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Clear separation of the combined colour and black and white signals, preventing smudging, vibrating edges and ensuring precise details
Hope this is of some help

Paul
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Old 04-07-2002, 11:11 PM   #3
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The comb filter achieves the clearer separation by subtracting the color signal taken from adjacent lines in the picture, so to 'comb' out the color from the luminance. A regular TV uses a notch filter, that simply cancels the frequency at which the color signal is found. That leaves some smearing, and limits the overall resolution.

Comb filters come in a variety of types, for instance a 2-line comb filter will subtract the color signal taken from each previous line, a 3-line comb filter will subtract the sum of the previous and subsequent lines, and a 3D comb filter will adapt its processing depending on motion. They can also be analog or digital with various pro's and con's to either. 3D comb filters are digital.

A comb filter permits both a reduction in interference between color and luminance, as well as a slightly higher resolution. In practice I think it is quite subtle, you are likely to see the most difference in a test card but not as much in typical video.

You usually cannot turn the comb filter off, but it will not activate in S-video or RGB signals since it is not applicable there. It will only be functional with composite signals (from an external device or the off-air RF feed).
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Old 04-07-2002, 11:38 PM   #4
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zacabeb, has the tosh 36zp18p got a comb filter?
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Old 04-07-2002, 11:58 PM   #5
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Originally posted by stranger
has the tosh 36zp18p got a comb filter?
Digital Comb Filter? Yes.
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Old 05-07-2002, 9:41 AM   #6
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thanks
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