[ITK-dev] [ITK] 2D/3D registration in v4

[David Burns]

Thanks Matt for your response.

For now I will proceed using metrics that don't require gradients.

At some point, it would be nice for the framework to handle 2D images in 
the 3D coordinate system.

Should we log this issue as a bug?

David

On 11/13/2015 06:11 PM, Matt McCormick wrote:
> Hi David,
>
> On Thu, Nov 12, 2015 at 9:51 PM, David Burns <david.mo.burns at gmail.com> wrote:
>> I think this issue relates to the way the metrics compute gradients. It can
>> be reproduced using
>>
>> Examples/RegistrationITKv4/ImageRegistration1.cxx
>> and
>> Examples/RegistrationITKv3/ImageRegistration1.cxx
>>
>> by setting Dimensions to 3, and using 2D images as inputs.
>>
>> I found using: metric->ComputeGradientOff()
>> will allow the registration to proceed for ITKv3 using the
>> MeanSquaresImageToImageMetric, but there is no such function for the v4
>> version.
>> Using a metric that does not require gradients (eg Mattes) will allow the
>> registration to proceed in both v3 and v4.
>>
>> I humbly suggest the registration framework and metrics should be able to
>> handle this situation. Also of note to those interested, the v3 registration
>> on my system goes about twice as fast per iteration.
> Patches would be welcome to improve the situation! Details on patch
> submission are here:
>
>    http://www.itk.org/Wiki/ITK/Git/Develop
>
>
> In terms of performance, we are creating a system of benchmarks so
> that we can quantify performance to make improvements and identify
> regressions.  The work is being added to this repository:
>
>    https://github.com/InsightSoftwareConsortium/ITKPerformanceBenchmarks
>
> The basic infrastructure will be in place in a few weeks time, after
> which you create a pull request for your use case. This will help make
> it possible to improve performance on your use case.
>
> Thanks,
> Matt