<br>Hi Pinpress,<br><br><br>The reason why the NormalizedMutualInformationHistogramImageToImageMetric<br>has not been converted to support multi-threading is simply that it wasn't a priority<br>at the time we engage in converting several of the metrics.<br>
<br><br>If you would like to volunteer to convert the metric we will be glad to provide you<br>guidance on how to do it.<br><br><br>Otherwise, if your immediate interest is simply to use a Normalized Mutual Information<br>
metric implementation (and doesn't have to be the Histogram-based one), then you <br>just need to modify the file:<br><br><ul><li>Insight/Code/Review/itkOptMattesMutualInformationImageToImageMetric.txx<br></li></ul><br>
in lines: 736-742.<br><br><br>As you probably know, the only difference between Mutual Information and<br>Normalized Mutual Information is how the joint entropy is combined at the<br>end with the entropy of the fixed and moving images. The computationally <br>
intensive part of the Metric is the section that computes the joint pdf, and <br>the individual pdfs, both of which happens before the lines of code listed <br>above.<br><br><br>Once you change these lines, you probably should also rename the class and<br>
we of course will strongly encourage you to submit it as a contribution to<br>the Insight Journal<br><br> <a href="http://www.insight-journal.org/">http://www.insight-journal.org/</a><br><br>which is one of the first steps for receiving contributions into the toolkit.<br>
<br>More details about this process are available at:<br><a href="http://www.vtk.org/Wiki/ITK_Procedure_for_Contributing_New_Classes_and_Algorithms">http://www.vtk.org/Wiki/ITK_Procedure_for_Contributing_New_Classes_and_Algorithms</a><br>
<br><br>We appreciate your constructive criticism and look forward to see<br>your contributions to the toolkit.<br><br><br> Best Regards,<br><br><br> Luis<br><br><br><br>-------------------------------------------------------------------------------------------------------------<br>
<div class="gmail_quote">On Sat, Nov 15, 2008 at 1:19 PM, pinpress <span dir="ltr"><<a href="mailto:sb_ji@yahoo.com">sb_ji@yahoo.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<br>
Hi all,<br>
<br>
I have built my ITK 3.10 by setting<br>
<br>
ITK_USE_REVIEW<br>
ITK_USE_OPTIMIZED_REGISTRATION_METHODS<br>
<br>
both to "ON" in CMake to take advantage of multithreading. I was very happy<br>
to find out that MattesMutualInformationImageToImageMetric image metric<br>
utilizes multi-cores automatically without even the need that I modify my<br>
code. However, NormalizedMutualInformationHistogramImageToImageMetric does<br>
not take multithreading! Any ideas why the latter is not multithreaded? I<br>
was able to find public member functions SetNumberOfThreads() in both image<br>
metrics.<br>
<br>
By the way, this forum does not seem to be very responsive at all -- I can<br>
see so many threads with literally zero reply. I wonder if this can be<br>
improved. I have been personally rather active in other technical forums<br>
(e.g., Mathworks) both asking questions and answering others questions. I<br>
think that's a very good experience there so far because many people there<br>
do the same. But I have to say that I am disappointed that this forum is not<br>
the case. I also hope that ITK become more powerful, robust, and versatile<br>
over the years, and more and more people will start to use it with more<br>
experience. I think this is the essence for the better good of open source<br>
software. But this would be difficult if without the help from more<br>
experienced users. Just my 2 cents.<br>
<font color="#888888">--<br>
View this message in context: <a href="http://www.nabble.com/why-Mattes-MI-is-multithreaded-but-Normalized-MI-is-not--tp20518131p20518131.html" target="_blank">http://www.nabble.com/why-Mattes-MI-is-multithreaded-but-Normalized-MI-is-not--tp20518131p20518131.html</a><br>
Sent from the ITK - Users mailing list archive at Nabble.com.<br>
<br>
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