I found the bug while working with that exact method, it's definitely worth revisiting.
-Kris On Apr 24, 2012, at 8:19 AM, Bradley Lowekamp <[email protected]> wrote: > This is a very interesting bug. That should require close attention. > > When I have as many cores as slices, does this bug mean that I have been > visiting each pixel multiple time? > > Also I think I encountered this bug when I was trying to multithread the > AnisotropicDiffusion's CalculateAverageGradientMagnitudeSquared method. I > should likely revisit that issue. > > Brad > > > > On Apr 19, 2012, at 3:44 AM, wanlin wrote: > >> I submitted a new patch. It should be able to handle all the cases. >> >> http://review.source.kitware.com/#/c/5213/ >> >> Cheer >> >> wanlin >> >> >> On Wed, Apr 18, 2012 at 5:41 PM, wanlin <[email protected]> wrote: >> >> In the case of [5,1], the image bufferedRegion is index[0,0], size[5,1]. >> requestToProcessRegion is the same as bufferedRegion. >> There is no NonBoundaryRegion with radius[1,1]. Meanwhile there is only one >> boundary region in the Y direction. >> >> I submit a patch which could address the issue. However it could not handle >> requestToProcessRegion is inside of BoundaryRegion. >> >> best >> >> >> wanlin >> >> On Wed, Apr 18, 2012 at 12:35 AM, Kris Zygmunt <[email protected]> wrote: >> >> On Apr 17, 2012, at 4:48 AM, wanlin wrote: >> >> >> Hi, >> The current implementation of BoundaryFacesCalculator is based on the >> following assumption. >> >> There is an overlap between requestToProcessRegion and nonBounaryRegion of >> BufferedRegion. >> >> Hence the first region in the output list is the nonBoundaryRegion in >> requestToProcessRegion. >> >> In your test, there is no overlap between requestToProcessRegion and >> bufferedRegion since requstToProcessRegion index[Dimension-1] = 1, which >> bufferedRegion index[Dimension - 1] = 0, size[Dimension - 1] = 1, . The >> ideal results ought to output 0 regions. >> >> Should we change the implementationso the calculator could deal with any >> cases of requestToProcessRegion and BufferedRegion? I am willing to put a >> patch. >> >> >> thanks >> >> >> wanlin >> >> >> I don't think the correct answer is 0 regions if the purpose of the >> calculator is to break the image up into regions for iteration. The best >> way to tell that it is working is that each pixel in the image should be >> visited once and only once when iterating across the union of the regions >> returned by the calculator. >> Let's look at two 2-D cases, a) [5,5] and b) [5,1]. >> >> In case a) the calculator returns the following regions: >> Index[1, 1], Size [3, 3], 9 pixels >> Index[0, 0], Size [1, 5], 5 pixels >> Index[4, 0], Size [1, 5], 5 pixels >> Index[1, 0], Size [3, 1], 3 pixels >> Index[1, 4], Size [3, 1], 3 pixels >> So all 25 pixels are visited once >> >> In case b), the calculator currently returns: >> Index[1, 1], Size [3, 0], 0 pixels (I think it is ok to return an empty >> region here as it indicates there are no interior points in the image) >> Index[0, 0], Size [1, 1], 1 pixel >> Index[4, 0], Size [1, 1], 1 pixel >> Index[1, 0], Size [3, 1], 3 pixels >> Index[1, 0], Size [3, 1], 3 pixels >> So 8 pixels are visited when there are only 5 pixels in the image. >> >> -Kris >> >> >> >> _______________________________________________ >> Powered by www.kitware.com >> >> Visit other Kitware open-source projects at >> http://www.kitware.com/opensource/opensource.html >> >> Kitware offers ITK Training Courses, for more information visit: >> http://kitware.com/products/protraining.php >> >> Please keep messages on-topic and check the ITK FAQ at: >> http://www.itk.org/Wiki/ITK_FAQ >> >> Follow this link to subscribe/unsubscribe: >> http://www.itk.org/mailman/listinfo/insight-developers > > ======================================================== > Bradley Lowekamp > Medical Science and Computing for > Office of High Performance Computing and Communications > National Library of Medicine > [email protected] > > >
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