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New Denoising/Smoothing Algorithm for Astronomical Images   Message List  
Reply | Forward Message #179 of 348 |
Re: New Denoising/Smoothing Algorithm for Astronomical Images

According to the  C++ library that GREYCstoration is based on it can support up to 4-D data. The C++ library is called CImg and you can read more about it at http://cimg.sourceforge.net/ . Here's and excerpt from that page stating its support for different data formats:

"
  • It contains useful image processing algorithms for image loading/saving, displaying, resizing/rotating, filtering, object drawing (text, lines, faces, curves, ellipses, 3D objects, ..), etc...
  • The main image class can represent images up to 4-dimension wide (x,y,z,v) (from 1-D scalar signals to 3-D multi-channel volumes), with template pixel types.
  • It depends on a minimal number of libraries : you can compile it only with standard C++ libraries. No need for exotic libraries and complex dependencies.
  • Additional features appear with the use of ImageMagick, libpng, libjpeg or XMedCon. Install the ImageMagick package or link your code with libpng and libjpeg to be able to load and save standard compressed image formats (GIF,BMP,TIF,JPG,PNG,...). Install the XMedCon package to be able to read DICOM medical image files. All these extra-tools are available for any platforms.
"

I would suggest going to the CImg website and look through the forum page to see what you can find. Since GREYCstoration is dependent on the CImg library, working with the C++ code is simplified for most editing tasks.

~Eli

 

--- In astro-viz@yahoogroups.com, "Werner Benger" <werner@...> wrote:
>
> Could this algorithm also be applied to 3D data?
> It might possibly be useful to apply it to three-dimensional data
> from numerical simulations that got some numerical noise as
> some postprocessing step prior to feature extraction.
>
> Werner
>
> On Thu, 15 Mar 2007 23:20:54 -0500, ebressert ebressert@... wrote:
>
> > Recently, a new algorithm based on anisotropic PDE's has been
> > released. The algorithm is written in C++ and is open source. You can
> > find the program, GREYCstoration, at
> > http://www.greyc.ensicaen.fr/~dtschump/greycstoration/ .
> >
> > The algorithm does quite well with denoising images while keeping the
> > structure of an object intact. The results are comparable to wavelet
> > smoothing processes that are found in other applications like MATLAB.
> >
> > In addition, the program utilizes the algorithm to process a function
> > called 'inpainting' to erase observational artifacts. This can
> > significantly ease the process of cleaning up an image.
> >
> > The third function of the GREYCstoration program is resizing. The
> > program appears to resize images comparable and sometimes better than
> > cubic functions. For examples of its abilities visit
> > http://www.greyc.ensicaen.fr/~dtschump/greycstoration/demonstration.html
> > . If you would like to see some astronomy examples visit
> > http://hea-www.harvard.edu/~ascpub/greyc/ . All the images have the
> > originals placed on the left hand side and the processed images on the
> > right.
> >
> > We'd like to start some discussion on this, send any feedback, or
> > ideas on this algorithm.
> >
> >
> > ~Eli
> >
> >
> >
> >
> > --------------------- Chandra X-ray Center ----------------------
> > Eli Bressert, Science Imager
> > http://chandra.harvard.edu
> >
> > Harvard-Smithsonian Center for Astrophysics
> > 60 Garden St. MS-67, Cambridge, MA 02138
> > -------------------------------------------------------------------
> >
> >
>
>
>
> --
> ___________________________________________________________________________
> Dr. Werner Benger werner@... Visualization Research
> Laboratory for Creative Arts and Technology (LCAT)
> Center for Computation & Technology at Louisiana State University (CCT/LSU)
> 300 Frey CSC, Baton Rouge, Louisiana 70803 Tel.: +1 225 578 7150
> or +1 225 334 2357 Fax.: +1 225 578-5362
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> "Here we have to deal with three dimensions, although we can only see two
> of them: height, direction and velocity." (Kiefer Sutherland as flight
> attendance in 'Collision Course: Panic in the Tower')
>


Fri Mar 16, 2007 4:13 pm

ebressert
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Message #179 of 348 |
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Recently, a new algorithm based on anisotropic PDE's has been released. The algorithm is written in C++ and is open source. You can find the program,...
ebressert
Offline Send Email
Mar 16, 2007
4:21 am

Could this algorithm also be applied to 3D data? It might possibly be useful to apply it to three-dimensional data from numerical simulations that got some...
Werner Benger
werner@...
Send Email
Mar 16, 2007
4:51 am

According to the C++ library that GREYCstoration is based on it can support up to 4-D data. The C++ library is called CImg and you can read more about it at...
ebressert
Offline Send Email
Mar 16, 2007
4:14 pm

Eli, Wow, that's a pretty intriguing algorithm, and the results with Chandra data are really impressive! Thanks for the heads-up! I'm itching to try it on some...
Robert Hurt
rhurt_spitzer
Offline Send Email
Mar 21, 2007
1:12 am

Hi Robert, After talking to some more people about the GREYCstoration algorithm, the installation procedure has been concluded to be a rather tedious and ...
ebressert
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Mar 26, 2007
3:39 pm
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