[Insight-users] [ITK Community] How to define range of value using in MI (Mattes)

[Luis Ibanez]

Hi Zoro


On Mon, Jan 20, 2014 at 3:03 AM, zoro <k09tranhoan at gmail.com> wrote:

> Dear all,
>
> I am performing registration between 3D volumes (chest before and after
> breathing) using Mattes MI & LBFGSBOptimizer. The result is pretty good but
> I need to improve it. Range of values in fixed image and moving image is
> (0,4000) with about 50 histogram bins number.
>
> The purpose of my work is to register cardiac parts but when using MI, it
> also registers bone parts. I want to define the range of value in volume to
> perform Mattes MI. For example, only in (0,1000) without modified the
> original volume. By the way, I used mask to concentrate at cardiac part and
> the result is also good.
>
> I wonder there is a method or not to define (min,max) using in MI. I
> attached part of MattesMutualInformation in ITK as I thought it related to
> this problem.
>
>


It looks like you may find useful the following methods:

SetFixedImageSamplesIntensityThreshold()
UseFixedImageSamplesIntensityThresholdOn()

http://www.itk.org/Doxygen/html/classitk_1_1ImageToImageMetric.html#ae18d98221d211736fc0448296e2c077c
http://www.itk.org/Doxygen/html/classitk_1_1ImageToImageMetric.html#ae56734d7cc4bb45a6ba462e56f260546


They allow you to define a minimum threshold to exclude pixels with
intensities lower than that, from participating in the computation of the
metric.

You could modify this code, in order to manage a range of intensities,
instead of just the lower threshold.

Places to look for inspiration are:

https://github.com/InsightSoftwareConsortium/ITK/blob/master/Modules/Registration/Common/include/itkImageToImageMetric.hxx#L581

and

https://github.com/InsightSoftwareConsortium/ITK/blob/master/Modules/Registration/Common/include/itkImageToImageMetric.hxx#L637



     Regards,


           Luis
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