Gaussian filter truncation #239
Conversation
This change gives the user control over the size at which the Gaussian filter is truncated, with default behavior to truncate at 4 standard deviations (the previous fixed value).
…gradient_magnitude() to gaussian_filter() This change allows control over the truncation radius of the gaussian filter used in gaussian_laplace() and gaussian_gradient_magnitude().
|
roderikk's original patch used But I don't like Perhaps the truncation amount should be specified in pixels. Also, should it be controllable in each dimension separately in |
|
Anyone want to have a look at this PR this week? Branching 0.12.x this weekend. |
|
Hi, I contributed the original bug in Trac. How can we get this pulled into main? I think that the truncation as a multiple of For me there is no need to to do a different value in each direction as that would only lead to very weird aliasing results. |
|
@roderikk: I'll take a look at this today.. I've been working on an enhancement for |
|
That sounds interesting. If you have some code to be tested let me know. |
|
@thouis: This looks like a good change. I prefer your 'truncate' over the original 'flen', and I don't have any better suggestions. (Anyone else have an opinion?) I like that you've allowed I've made a pull request on your repo with some changes to the test: thouis#1 |
|
Continued in gh-2767 |
|
I realize this is closed, but I've been thinking about a related issue: as sigma goes to zero, the default behavior is ugly: when s goes below 0.25, gaussian_filter suddenly does nothing. Since performance isn't really an issue with a kernel size of three pixels, I would prefer that the kernel not become a delta function until sigma is exactly zero. Thoughts? |
|
@BenFrantzDale: please open a new issue, thanks. |
These changes add control over the radius of truncation of the Gaussian filters in scipy.ndimage, and add the ability to pass keyword arguments through gaussian_laplace()/gaussian_gradient_magnitude() to gaussian_filter().
This is an expanded form of roderikk's patch from this ticket:
http://projects.scipy.org/scipy/ticket/1660