arbitrary size kernel
- To: mathgroup at smc.vnet.net
- Subject: [mg101547] arbitrary size kernel
- From: "alexxx.magni at gmail.com" <alexxx.magni at gmail.com>
- Date: Fri, 10 Jul 2009 06:41:59 -0400 (EDT)
while I understand a bit the logic behind filtering in the frequency domain, I have a problem with filtering by convolution. I'd like to understand how to construct arbitrary-size kernels: which are the requirements? Specifically, I need to build the kernel of a high-pass filter able to filter everything below some freq f_0. My problem is that all the descriptions I found are usually for kernels in the 3x3 form, e.g. ((0.0, -1.0, 0.0),(-1.0, 5.0, -1.0),(0.0, -1.0, 0.0)) What I cannot understand is: which is the relationship between the cutoff frequency and a given kernel shape? The kernel size? The step between central element and side elements? thanks for any hints or suggestions... alessandro