Butterworth Kernel?

[babaq]

Hi,

I can't find a butterworth kernel in the Images, and think would be a nice addition to the package.

The DSP.jl do have a Butterworth filter design, maybe could be used or looked up to generate the Factored Kernels.

Alex

[johnnychen94]

Yes, it's a good addition, can you open a PR to ImageFiltering? That's where most of the kernels lives.

[babaq]

I would like to contribute, but may not have the technical competence to implement the kernel, at least in a short period of time.

[johnnychen94]

You can take a look at #147 as an example. Some source codes, docstrings, and test cases should be sufficient.