Low Pass Filter in PS


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yanyewkay

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Sep 22, 2004
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Cons digger.
There's a High Pass Filter in PS.. but does anyone know the matrix for a LPF using the 'custom' feature?

most sites out there only describe what is available in PS.. the best explanation i find being from escrappers.

Anyone can help? TIA
 

yanyewkay said:
There's a High Pass Filter in PS.. but does anyone know the matrix for a LPF using the 'custom' feature?

most sites out there only describe what is available in PS.. the best explanation i find being from escrappers.

Anyone can help? TIA

You can simply use "gaussian blur", which is a low-pass filter.
 

yanyewkay said:
yups thanks.. i read that on http://www.escrappers.com/filters13.html I just wanted to know how to implement it with the custom function. Thinking of using LPF as a basis to try out if some other stuff works. :p thanks anyway.

Somewhat/much simplified, a high pass filter emphasizes the differences between neighboring pixels, so the filter coefficients change signs. A low pass filter suppresses the differences (it averages over neighboring pixels), so you can try a filter kernel without sign changes. (This is not strictly true, but I hops you get the idea.) Also note that "high pass" and "low pass" is a very general classification; there's an infinite number of different filters that fall into these groups.
 

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