# ITK Error

**URL:** <https://discourse.itk.org/t/itk-error/6521>\
**Category:** Uncategorized\
**Created:** [March 18, 2024, 6:22am UTC](https://discourse.itk.org/t/itk-error/6521 "2024-03-18T06:22:14Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![skb](https://discourse.itk.org/letter_avatar_proxy/v4/letter/s/c77e96/32.png) [@skb](https://discourse.itk.org/u/skb)\
**Post date:** [March 18, 2024, 6:22am UTC](https://discourse.itk.org/t/itk-error/6521/1 "2024-03-18T06:22:14Z")

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itk::ExceptionObject (00000079F50FBB38)  
Location: “class itk::SmartPointer\<class itk::RealToHalfHermitianForwardFFTImageFilter\<class itk::Image\<float,3\>,class itk::Image\<class std::complex,3\> \> \> \_\_cdecl itk::RealToHalfHermitianForwardFFTImageFilter\<class itk::Image\<float,3\>,class itk::Image\<class std::complex,3\> \>::New(void)”  
File: D:\InsightToolkit-5.4rc01\Modules\Filtering\FFT\include\itkRealToHalfHermitianForwardFFTImageFilter.h  
Line: 85  
Description: ITK ERROR: Object factory failed to instantiate class itk::RealToHalfHermitianForwardFFTImageFilter\<class itk::Image\<float,3\>,class itk::Image\<class std::complex,3\> \>  
because i found that my procedure runs unnormally between 2 computers(a normal computer runs faster than a better equiped one),i guass it’s for my compiling RTK libariries,and i have tried so many ways to test the real problem,but got nothing,so i try to compile a new version,ITK5.4,according to the decription,RTK is a Module of ITK in 5.4,so i just compile ITK,finally i got RTK’s libariries,after relacing the dll and lib,i rebuild my software,but it shows error message as mentioned above,it means instantiating a object of itk::RealToHalfHermitianForwardFFTImageFilter\<class itk::Image\<float,3\>,class itk::Image\<class std::complex,3\> \> failed,i don’t know how it comes,i didn’t call this filter,it should be a procss in FDK filter,i can’t got the detail message.please give some advice,thank you!

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**Author:** ![simon.rit](https://discourse.itk.org/letter_avatar_proxy/v4/letter/s/f08c70/32.png) [@simon.rit](https://discourse.itk.org/u/simon.rit)\
**Post date:** [March 19, 2024, 10:33am UTC](https://discourse.itk.org/t/itk-error/6521/2 "2024-03-19T10:33:15Z")

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You mention in a private message that this is while using RTK. I don’t know why the object factory fails. Do you have the same problem with the [FirstReconstruction](https://github.com/RTKConsortium/RTK/blob/master/examples/FirstReconstruction/) example? If not, maybe something is missing in your [CMakeLists.txt](https://github.com/RTKConsortium/RTK/blob/master/examples/FirstReconstruction/CMakeLists.txt)?

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**Author:** ![skb](https://discourse.itk.org/letter_avatar_proxy/v4/letter/s/c77e96/32.png) [@skb](https://discourse.itk.org/u/skb)\
**Post date:** [March 20, 2024, 12:42am UTC](https://discourse.itk.org/t/itk-error/6521/3 "2024-03-20T00:42:39Z")

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i just test FirstReconstruction demo,it dose have the same problem,what is missing in Cmakelists.txt,i download the source package from ITK’s Website,and i do not change anything.

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**Author:** ![skb](https://discourse.itk.org/letter_avatar_proxy/v4/letter/s/c77e96/32.png) [@skb](https://discourse.itk.org/u/skb)\
**Post date:** [March 20, 2024, 1:06am UTC](https://discourse.itk.org/t/itk-error/6521/4 "2024-03-20T01:06:25Z")

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here are the cmakelists.txt,one for ITK5.4 and the other one for RTK  
[CMakeLists.txt](https://discourse.itk.org/uploads/short-url/J0yhx87qXn5BSPqwLhKPZHrxdN.txt) (30.3 KB)  
[CMakeLists.txt](https://discourse.itk.org/uploads/short-url/fFDNQhLjfXPlcQ4K5cBWLsKLsiy.txt) (10.3 KB)