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<P><FONT SIZE=2>Hello,<BR>
<BR>
I am fairly new to ITK so I apologize in advance for this question...<BR>
<BR>
I am using an AffineTransform to perform image registration. I know<BR>
for example that the rotation I am looking for will be between -10<BR>
and 10 degrees. For a specific test, it is about one degree.<BR>
<BR>
I initialize the transform like this:<BR>
<BR>
// set initial transform matrix to identity and rotation center to image center<BR>
typedef itk::CenteredTransformInitializer< TransformType, FixedImageType, MovingImageType > TransformInitializerType;<BR>
typename TransformInitializerType::Pointer initializer = TransformInitializerType::New();<BR>
initializer->SetTransform( transform );<BR>
initializer->SetFixedImage( fixedImageReader->GetOutput() );<BR>
initializer->SetMovingImage( movingImageReader->GetOutput() );<BR>
initializer->GeometryOn();<BR>
initializer->InitializeTransform();<BR>
typename RegistrationType::ParametersType initialParameters = transform->GetParameters();<BR>
initialParameters[0] = 1.0;<BR>
initialParameters[1] = 0.0;<BR>
initialParameters[2] = 0.0;<BR>
initialParameters[3] = 1.0;<BR>
registration->SetInitialTransformParameters( initialParameters );<BR>
<BR>
Now when I run this, the first iteration of the registration process yields:<BR>
<BR>
Using initial center of rotation: (1751.5, 1167.5)<BR>
Using initial translation: (0, 0)<BR>
Using initial scale 1: 1<BR>
Using initial scale 2: 1<BR>
Using initial angle (degrees): 0<BR>
<BR>
Registration iterations:<BR>
0 = -0.6493 : [1.05913, 0.261505, -0.394698, 1.10742, -0.00464574, -0.103787]<BR>
Affine angle: -16.8505<BR>
<BR>
Now I wonder why it is -16.8505 degrees initially... I'd like to start at 0 degrees and look<BR>
in a range of -10 to 10. Is there a way to achieve this ?<BR>
<BR>
Thanks in advance !<BR>
<BR>
<BR>
guillaume<BR>
<BR>
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