2011/12/12 Stéfan van der Walt <stefan@sun.ac.za>

Hi TJ

On Mon, Dec 12, 2011 at 2:27 PM, karoyakani <tj.takei@gmail.com> wrote:

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I'm new to this mailing list.

Welcome! We're glad to have you.

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skimage version 0.4.2 has morphology.skeletonize() that works almost as good as Matlab bwmorph('thin').

We'd certainly love to remedy that...

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However the output seems transposed when I tested a Matlab's example image 'circles.png': http://www.mathworks.com/help/toolbox/images/ref/bwmorph.html Is this a bug?

In order to reproduce this bug, I've put a repo online with your code:

https://github.com/stefanv/skimage_circles

Here is the output I get:

http://mentat.za.net/refer/skeletonize_compare.png

(Before running the experiment, run fetch_data to download the matlab test image; or just grab it by hand from their website. I don't know what the license is, so I didn't want to put it in the repo directly.)

I am glad you showed me this example, because it also pointed out a problem with paletted image reading in PIL. I'm seriously considering just making matplotlib our default backend (except that they also have a PNG reading bug in older versions where images are flipped upside down!).

Regards Stéfan

Strange: when I open "circles.png" using the matplotlib backend, I get a float32 array (with the white pixels equal to 0.00392157). With the PIL backend, I get a bool array (before your recent bug fix) or uint8 (after the fix). Are you not having the same issue with matplotlib? -Tony