// ********** Image Types

(FixedInternalImagePixelType "float")
(FixedImageDimension 3)
(MovingInternalImagePixelType "float")
(MovingImageDimension 3)


// ********** Components

(Registration "MultiResolutionRegistration")
(FixedImagePyramid "FixedSmoothingImagePyramid")
(MovingImagePyramid "MovingSmoothingImagePyramid")
(Interpolator "BSplineInterpolator")
(Metric "AdvancedMattesMutualInformation")
(Optimizer "StandardGradientDescent")
(ResampleInterpolator "FinalBSplineInterpolator")
(Resampler "DefaultResampler")
(Transform "BSplineTransform")


// ********** Pyramid

// Total number of resolutions
(NumberOfResolutions 6)
// default schedule: isotropic upsampling with factor 2

// ********** Transform

(FinalGridSpacingInPhysicalUnits 12.0 12.0 12.0)
(GridSpacingSchedule 1.0 1.0 1.0 1.0 1.0 1.0)
(HowToCombineTransforms "Compose")

//Save composite ITK transform
(ITKTransformOutputFileNameExtension "h5")
(WriteITKCompositeTransform "true")


// ********** Optimizer

// Maximum number of iterations in each resolution level:
(MaximumNumberOfIterations 1000)

//SP: Param_a in each resolution level. a_k = a/(A+k+1)^alpha
(SP_a 10000.0)

//SP: Param_alpha in each resolution level. a_k = a/(A+k+1)^alpha
(SP_alpha 0.602)

//SP: Param_A in each resolution level. a_k = a/(A+k+1)^alpha
(SP_A 50.0)


// ********** Metric

//Number of grey level bins in each resolution level:
(NumberOfHistogramBins 32)
(FixedLimitRangeRatio 0.0)
(MovingLimitRangeRatio 0.0)
(FixedKernelBSplineOrder 1)
(MovingKernelBSplineOrder 3)


// ********** Several

(WriteTransformParametersEachIteration "false")
(WriteTransformParametersEachResolution "true")
(WriteResultImageAfterEachResolution "false")
(WriteResultImage "false")
(ShowExactMetricValue "false")
(ErodeMask "false")


// ********** ImageSampler

//Number of spatial samples used to compute the mutual information in each resolution level:
(ImageSampler "RandomSparseMask")
(NumberOfSpatialSamples 2000)
(NewSamplesEveryIteration "true")
(UseRandomSampleRegion "false")


// ********** Interpolator and Resampler

//Order of B-Spline interpolation used in each resolution level:
(BSplineInterpolationOrder 1)

//Order of B-Spline interpolation used for applying the final deformation:
(FinalBSplineInterpolationOrder 3)

//Default pixel value for pixels that come from outside the picture:
(DefaultPixelValue 0)

