[Insight-users] Affine+Mattes 2D registration problem

[sharath v]

Hi,

I am also facing the same problem.

In ImageRegistration2.cxx example it is mentioned that RegularStepGradientDescentOptimizer should not be used, as values are noisy. Hence I tried to use AmoebaOpitimizer and OnePlusOneOptimizer with Mattes + AffineTransform. But in both cases, I do get an exception of 

Description: itk::ERROR: MattesMutualInformationImageToImageMetric(00F1F5F0): Too many samples map outside moving image buffer: 0 / 10000

in the first iteration of registration

I have used both CenteredTransformInitializer andoptimizer->SetScales( optimizerScales ), and the output of the warp on the initializer parameters look correct.

Can you please let me know how to overcome this problem?

Thanks,
Sharath Venkatesha






________________________________
From: Manuel David Tabas Calle <manueldavid.tabas at hotmail.es>
To: ITK <insight-users at itk.org>
Sent: Wednesday, June 24, 2009 4:21:40 AM
Subject: [Insight-users] Affine+Mattes 2D registration problem

 Hi!
 
I have a problem using an Affine transform with Mattes Mutual metric. 
 
When I used an Affine transform, with MeanSquaresImageToImageMetric, my registration works perfectly, but it is really slow because my images are big (it last for 45 minutes). My images are between 2000x2000 and 4000x4000 pixels, with spacig of (1,1,1). 
 
So i decided to use MattesMutualInformationImageToImageMetric, that is a faster metric. But the results are not good.
 
 
In both, I used the followin parameters:
 
optimizerScales[0] = 1.0;
optimizerScales[1] = 1.0;
optimizerScales[2] = 1.0;
optimizerScales[3] = 1.0;
optimizerScales[4] = 1.0/1000.0;
optimizerScales[5] = 1.0/1000.0;
 
steplength = 0.1
 
maxNumberOfIterations = 300;
 
minimumStepLength = 0.0001;
 
and 
 
optimizer->MinimizeOn();
 
For the Mattes Mutual metric, I tried a lot of combinations of histogram bins and spatial samples, starting with 50 bins and a 20% of the pixels as spatial samples. But no matter what i try, the results are not good.
 
In both programs, i use LinearInterpolateImageFunction and RegularStepGradientDescentOptimizer.
 
How can I tune the parameters of the program with MattesMutual to obtain the same results???
 
Thank you all!!!

________________________________
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