Multispectral random walker segmentation

[Emmanuelle Gouillart]

Wow, that was quick :-), thanks!

I'll have a look tomorrow, I'm just back from Brussels and Euroscipy!

Emmanuelle

On Mon, Aug 27, 2012 at 02:18:22PM -0700, Josh Warner wrote:
>    Pull request is up! �I also fixed a bug in the fallback call of
>    _solve_cg() if pyamg is not installed. �Comments appreciated.
>    Josh
>    On Monday, August 27, 2012 7:55:11 AM UTC-5, Emmanuelle Gouillart wrote:

>      Hi Josh,

>      my changes have been merged, so if you pull from github they are in
>      the master branch now, you can add your changes and make a pull request!

>      Cheers,
>      Emmanuelle

>      On Thu, Aug 23, 2012 at 02:50:05PM -0700, Josh Warner wrote:
>      > � �I'd be happy to include your suggested changes, if it's simpler to
>      go that
>      > � �route than have two separate pull requests. �I don't want to step
>      on any
>      > � �toes regarding attribution, though. �
>      > � �Having the 'soft' probabilities available is definitely a useful
>      > � �improvement (cleanup, fuzzy post-processing), and I'm glad you
>      implemented
>      > � �that! �
>      > � �Josh

>      > � �On Monday, August 20, 2012 4:11:45 PM UTC-5, Emmanuelle Gouillart
>      wrote:

>      > � � �Hi Josh,

>      > � � �extending the random walker algorithm to multichannel images
>      sounds like
>      > � � �a very nice idea, and I'm sure that it would be useful for other
>      people
>      > � � �(including myself!).

>      > � � �In fact, I had started working on some improvements of the random
>      walker
>      > � � �code but didn't go as far as proposing the pull request. I have a
>      branch
>      > � � �for that on
>      > � �
>      �[1][1]https://github.com/emmanuelle/scikits.image/tree/fix_random_walker,
>      > � � �maybe
>      > � � �you can include these changes when you contribute your changes?

>      > � � �Cheers,
>      > � � �Emmanuelle

>      > � � �On Mon, Aug 20, 2012 at 10:03:53AM -0700, Josh Warner wrote:
>      > � � �> � �I have modified the existing random walker algorithm
>      into a fully
>      > � � �> � �backwards-compatible version which allows inclusion of
>      > � � �multispectral data,
>      > � � �> � �e.g. RGBA channels or different (registered) image
>      modalities. �I
>      > � � �really
>      > � � �> � �liked the existing algorithm, so I just extended it
>      rather than
>      > � � �write one
>      > � � �> � �from scratch for my own purposes. �The overhead is
>      minimal;
>      > � � �multispectral
>      > � � �> � �processing is triggered if data is passed as an iterable
>      of arrays
>      > � � �rather
>      > � � �> � �than just an array. �
>      > � � �> � �This amounts to combining image gradients as
>      sqrt(sum-of-squares)
>      > � � �and
>      > � � �> � �dividing by sqrt(#channels). �For obvious reasons, the
>      several
>      > � � �channels
>      > � � �> � �must be pre-processed to have data on similar ranges by
>      whitening
>      > � � �or a
>      > � � �> � �similar method. �Not usually a problem for RGB, but in
>      medical
>      > � � �imaging
>      > � � �> � �this rears its head.
>      > � � �> � �Would this be of interest to the community? �I'd be
>      happy to
>      > � � �contribute
>      > � � �> � �the changes if there is interest.

>      > References

>      > � �Visible links
>      > � �1.
>      [2]https://github.com/emmanuelle/scikits.image/tree/fix_random_walker

> References

>    Visible links
>    1. https://github.com/emmanuelle/scikits.image/tree/fix_random_walker
>    2. https://github.com/emmanuelle/scikits.image/tree/fix_random_walker