[Insight-users] itkGradientDifferenceImageToImageMetric

[Lorensen, William E (Research)]

Thanks for the bug report. I think I fixed it. It never worked apparently.

You will need to update:

Code/Commono/itkTranslateTransform.txx
Code/Algorithms/itkGradientDifferenceImageToImageMetric.txx and .h
Testing/Code/Algorithm/itkGradientDifferenceImageToImageMetricTest.cxx

Now, the values change. I'm not sure if thet are correct. If you find that it works as expected (or not), let us know.

Bill

-----Original Message-----
From: Vicente Grau [mailto:vicente at robots.ox.ac.uk]
Sent: Thursday, December 01, 2005 11:42 AM
To: Lorensen, William E (Research); insight-users at itk.org
Subject: Re: [Insight-users] itkGradientDifferenceImageToImageMetric


Thanks very much, I have already placed a bug report (number 2543). How 
can I know when this has been fixed?

Vicente


Lorensen, William E (Research) wrote:

>As you discovered, this filter is badly broken. I've looked at the code this morning and found a few problems already.
>
>As Karthik suggested, you should log a bug for itk at:
>http://www.itk.org/Bug/index.php
>
>Believe it or not, we do look at these.
>
>Bill
>
>
>
>-----Original Message-----
>From: insight-users-bounces+lorensen=crd.ge.com at itk.org
>[mailto:insight-users-bounces+lorensen=crd.ge.com at itk.org]On Behalf Of
>Vicente Grau
>Sent: Wednesday, November 30, 2005 1:07 PM
>To: insight-users at itk.org
>Subject: [Insight-users] itkGradientDifferenceImageToImageMetric
>
>
>I have been comparing several image-to-image metrics using a 
>modification of the program MeanSquaresImageMetric1.cxx. With 
>GradientDifferenceImageToImageMetric, I get a constant value, 
>independent of the translation between the images (e.g., in case of two 
>3D images, 40x60x60 voxels, intensity range 0-255, the value is always 
>339204.)
>I have only found an example that uses this metric, it is one of the 
>tests of itkAlgorithmsTests2.exe. When I run it, I get the result below. 
>It seems to me that this result has exactly the same problem: the same 
>value 20000 regardless of the translation values (and derivatives equal 
>to 0). Is this the expected result for this test? Is the metric working 
>well?
>
>------------------------
>Available tests:
>...
>3. itkGradientDifferenceImageToImageMetricTest
>...
>To run a test, enter the test number: 3
>
>Parameters: [-50, -50], Value: 20000, Derivatives: [0, 0]
>Parameters: [-25, -50], Value: 20000, Derivatives: [0, 0]
>Parameters: [0, -50], Value: 20000, Derivatives: [0, 0]
>Parameters: [25, -50], Value: 20000, Derivatives: [0, 0]
>Parameters: [50, -50], Value: 20000, Derivatives: [0, 0]
>Parameters: [-50, -25], Value: 20000, Derivatives: [0, 0]
>Parameters: [-25, -25], Value: 20000, Derivatives: [0, 0]
>Parameters: [0, -25], Value: 20000, Derivatives: [0, 0]
>Parameters: [25, -25], Value: 20000, Derivatives: [0, 0]
>Parameters: [50, -25], Value: 20000, Derivatives: [0, 0]
>Parameters: [-50, 0], Value: 20000, Derivatives: [0, 0]
>Parameters: [-25, 0], Value: 20000, Derivatives: [0, 0]
>Parameters: [0, 0], Value: 20000, Derivatives: [0, 0]
>Parameters: [25, 0], Value: 20000, Derivatives: [0, 0]
>Parameters: [50, 0], Value: 20000, Derivatives: [0, 0]
>Parameters: [-50, 25], Value: 20000, Derivatives: [0, 0]
>Parameters: [-25, 25], Value: 20000, Derivatives: [0, 0]
>Parameters: [0, 25], Value: 20000, Derivatives: [0, 0]
>Parameters: [25, 25], Value: 20000, Derivatives: [0, 0]
>Parameters: [50, 25], Value: 20000, Derivatives: [0, 0]
>Parameters: [-50, 50], Value: 20000, Derivatives: [0, 0]
>Parameters: [-25, 50], Value: 20000, Derivatives: [0, 0]
>Parameters: [0, 50], Value: 20000, Derivatives: [0, 0]
>Parameters: [25, 50], Value: 20000, Derivatives: [0, 0]
>Parameters: [50, 50], Value: 20000, Derivatives: [0, 0]
>GradientDifferenceImageToImageMetric (0198CE00)
>  RTTI typeinfo:   class itk::GradientDifferenceImageToImageMetric<class 
>itk::Image<double,2>,class itk::Image<double,2> >
>  Reference Count: 1
>  Modified Time: 50
>  Debug: Off
>  Observers:
>    none
>  ComputeGradient: 1
>  Moving Image: 0198A938
>  Fixed  Image: 0198CAA0
>  Gradient Image: 019C85A0
>  Transform:    01987800
>  Interpolator: 019C82B0
>  FixedImageRegion: ImageRegion (0198CE54)
>  Dimension: 2
>  Index: [0, 0]
>  Size: [100, 100]
>
>  Moving Image Mask: 00000000
>  Fixed Image Mask: 00000000
>  Number of Pixels Counted: 0
>Test passed.
>
>
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