Mailman 3 October 2012 - scikit-image

Re: Reading .jp2 in skimage
by Tony Yu Oct. 29, 2012

Oct. 29, 2012

On Mon, Oct 29, 2012 at 6:23 PM, Jaidev Deshpande < deshpande.jaidev(a)gmail.com> wrote: > On Tue, Oct 30, 2012 at 3:39 AM, Tony Yu <tsyu80(a)gmail.com> wrote: > > > > > > On Mon, Oct 29, 2012 at 5:53 PM, Jaidev Deshpande > > <deshpande.jaidev(a)gmail.com> wrote: > >> > > <snip> > > > > skimage doesn't implement image readers, but instead, uses other i/o > > libraries as plugins (so there's no good way to list image format > support). > > Out of curiosity, does matplotlib's imread do the same, using other > plugins? > I think Matplotlib uses libpng for PNGs and then PIL for everything else. I tried loading a jp2 image with the matplotlib plugin and it raises a PIL error. > For me, `skimage.io.imread` doesn't read jp2 by default (my default plugin > > is 'PIL'), but I can set the plugin to 'freeimage' to read jp2 images; > e.g. > > > > from skimage import io > > io.imread('some_image.jp2', plugin='freeimage') > > > > which uses freeimage just for that one call or > > > > io.use_plugin('freeimage') > > io.imread('some_image.jp2') > > > > which changes your default io plugin to freeimage. You'd need to have the > > freeimage library installed on your system to use this plugin: > > > > http://freeimage.sourceforge.net/ > > Thanks! That did it. > Great! We should probably update info in the docs about what plugins we support. Freeimage is already listed in our install page, but there are actually a few others that aren't: http://scikit-image.org/docs/dev/install.html

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Re: Reading .jp2 in skimage
by Jaidev Deshpande Oct. 29, 2012

Oct. 29, 2012

On Tue, Oct 30, 2012 at 3:39 AM, Tony Yu <tsyu80(a)gmail.com> wrote: > > > On Mon, Oct 29, 2012 at 5:53 PM, Jaidev Deshpande > <deshpande.jaidev(a)gmail.com> wrote: >> >> Hello, >> >> Are jpeg 2000 images supported in skimage? I tried looking for it in >> the docs but didn't find anything. >> >> Thanks >> >> -- >> JD >> > > Hey JD, > > skimage doesn't implement image readers, but instead, uses other i/o > libraries as plugins (so there's no good way to list image format support). Out of curiosity, does matplotlib's imread do the same, using other plugins? > For me, `skimage.io.imread` doesn't read jp2 by default (my default plugin > is 'PIL'), but I can set the plugin to 'freeimage' to read jp2 images; e.g. > > from skimage import io > io.imread('some_image.jp2', plugin='freeimage') > > which uses freeimage just for that one call or > > io.use_plugin('freeimage') > io.imread('some_image.jp2') > > which changes your default io plugin to freeimage. You'd need to have the > freeimage library installed on your system to use this plugin: > > http://freeimage.sourceforge.net/ Thanks! That did it. > > There may be other skimage plugins that support jp2, but I'm not sure. > > Best, > -Tony > > -- > > -- JD

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Re: Reading .jp2 in skimage
by Tony Yu Oct. 29, 2012

Oct. 29, 2012

On Mon, Oct 29, 2012 at 5:53 PM, Jaidev Deshpande < deshpande.jaidev(a)gmail.com> wrote: > Hello, > > Are jpeg 2000 images supported in skimage? I tried looking for it in > the docs but didn't find anything. > > Thanks > > -- > JD > > Hey JD, skimage doesn't implement image readers, but instead, uses other i/o libraries as plugins (so there's no good way to list image format support). For me, `skimage.io.imread` doesn't read jp2 by default (my default plugin is 'PIL'), but I can set the plugin to 'freeimage' to read jp2 images; e.g. from skimage import io io.imread('some_image.jp2', plugin='freeimage') which uses freeimage just for that one call or io.use_plugin('freeimage') io.imread('some_image.jp2') which changes your default io plugin to freeimage. You'd need to have the freeimage library installed on your system to use this plugin: http://freeimage.sourceforge.net/ There may be other skimage plugins that support jp2, but I'm not sure. Best, -Tony

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Reading .jp2 in skimage
by Jaidev Deshpande Oct. 29, 2012

Oct. 29, 2012

Hello, Are jpeg 2000 images supported in skimage? I tried looking for it in the docs but didn't find anything. Thanks -- JD

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Re: Motion deblurring challenge
by Christoph Gohlke Oct. 26, 2012

Oct. 26, 2012

On 10/24/2012 2:27 PM, StÃ¯Â¿Â½fan van der Walt wrote: > Hi, all > > Every year, I give the students in our image processing course the > challenge of deblurring the following image: > > https://github.com/stefanv/scikit-image-demos/blob/master/data/clock_motion… > > Now, the question is whether the experts on this mailing list decipher > the time on the wall clock! > > Here's my attempt so far: > https://github.com/stefanv/scikit-image-demos/blob/master/clock_deblur.py > -- mine tells the time already, so don't look if you want to figure > this one out yourself. > > Cheers > StÃ¯Â¿Â½fan > A Q&D deconvolution with a kernel guesstimated from the blurred image (~35 px horizontally) seems to be good enough to read the time. Christoph

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Re: Motion deblurring challenge
by Johannes Schönberger Oct. 25, 2012

Oct. 25, 2012

Hi, hopefully I'll have time to try to solve this. Unfortunately I'm short of time at the moment... Johannes Schönberger Am 24.10.2012 um 23:28 schrieb "Stéfan van der Walt" <stefan(a)sun.ac.za>: > Hi, all > > Every year, I give the students in our image processing course the > challenge of deblurring the following image: > > https://github.com/stefanv/scikit-image-demos/blob/master/data/clock_motion… > > Now, the question is whether the experts on this mailing list decipher > the time on the wall clock! > > Here's my attempt so far: > https://github.com/stefanv/scikit-image-demos/blob/master/clock_deblur.py > -- mine tells the time already, so don't look if you want to figure > this one out yourself. > > Cheers > Stéfan > > -- > >

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Motion deblurring challenge
by Stéfan van der Walt Oct. 24, 2012

Oct. 24, 2012

Hi, all Every year, I give the students in our image processing course the challenge of deblurring the following image: https://github.com/stefanv/scikit-image-demos/blob/master/data/clock_motion… Now, the question is whether the experts on this mailing list decipher the time on the wall clock! Here's my attempt so far: https://github.com/stefanv/scikit-image-demos/blob/master/clock_deblur.py -- mine tells the time already, so don't look if you want to figure this one out yourself. Cheers Stéfan

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LPI filter framework redesign
by Stéfan van der Walt Oct. 24, 2012

Oct. 24, 2012

Hi all, I just revisited the LPI filter framework for the first time in many years, and...err...it's pretty bad :) I wrote this originally to simulate the effect of a specific point-spread-function on an image--and for that purpose it works OK. But for restoring images based on a kernel, the interface doesn't work. I'd like to redesign this functionality, and would like to have your input. Does anyone here have much experience in this type of filtering and deblurring images? My bigger aim is to implement fairly robust blind deconvolution. Stéfan

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Re: De-Blurring
by Stéfan van der Walt Oct. 22, 2012

Oct. 22, 2012

On Mon, Oct 22, 2012 at 12:05 AM, Guillaume Calmettes <guillaume.calmettes(a)gmail.com> wrote: > I just went through an interesting post on restoration of defocused and > blurred images (with Matlab code provided), that you might find interesting: > http://yuzhikov.com/articles/BlurredImagesRestoration1.htm Blind decovolution is high up on my priority list for skimage. In the mean time, improving the existing Wiener inverse filter to support kernels would be good. Also, adding Thikonov's inverse method. Thanks for the link! Stéfan

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De-Blurring
by Guillaume Calmettes Oct. 22, 2012

Oct. 22, 2012

Hello, I just went through an interesting post on restoration of defocused and blurred images (with Matlab code provided), that you might find interesting: http://yuzhikov.com/articles/BlurredImagesRestoration1.htm guillaume

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