# Description: ITK ERROR: Object factory failed to instantiate class itk::RealToHalfHermitianForwardFFTImageFilter\<class itk::Image\<double,3\>,class itk::Image\<class std::complex\<double\>,3\> \>

**URL:** https://discourse.itk.org/t/description-itk-error-object-factory-failed-to-instantiate-class-itk-realtohalfhermitianforwardfftimagefilter-class-itk-image-double-3-class-itk-image-class-std-complex-double-3/5865
**Category:** Engineering
**Created:** [April 12, 2023, 5:49am UTC](https://discourse.itk.org/t/description-itk-error-object-factory-failed-to-instantiate-class-itk-realtohalfhermitianforwardfftimagefilter-class-itk-image-double-3-class-itk-image-class-std-complex-double-3/5865 "2023-04-12T05:49:34Z")
**Posts on this page:** 4
**Page:** 1

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### Author: ![ma1282029525](https://discourse.itk.org/user_avatar/discourse.itk.org/ma1282029525/32/3084_2.png) [@ma1282029525](https://discourse.itk.org/u/ma1282029525)
#### Post date: [April 12, 2023, 5:49am UTC](https://discourse.itk.org/t/description-itk-error-object-factory-failed-to-instantiate-class-itk-realtohalfhermitianforwardfftimagefilter-class-itk-image-double-3-class-itk-image-class-std-complex-double-3/5865/1 "2023-04-12T05:49:34Z")

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The version attempted to use the RTK library, and there was no problem running the test program. I copied the example in the example and encountered this error.

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### Author: ![ma1282029525](https://discourse.itk.org/user_avatar/discourse.itk.org/ma1282029525/32/3084_2.png) [@ma1282029525](https://discourse.itk.org/u/ma1282029525)
#### Post date: [April 12, 2023, 9:00am UTC](https://discourse.itk.org/t/description-itk-error-object-factory-failed-to-instantiate-class-itk-realtohalfhermitianforwardfftimagefilter-class-itk-image-double-3-class-itk-image-class-std-complex-double-3/5865/2 "2023-04-12T09:00:01Z")

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After recompiling the library twices, it became normal.

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### Author: ![xiejunjie](https://discourse.itk.org/letter_avatar_proxy/v4/letter/x/9de0a6/32.png) [@xiejunjie](https://discourse.itk.org/u/xiejunjie)
#### Post date: [April 21, 2023, 9:47am UTC](https://discourse.itk.org/t/description-itk-error-object-factory-failed-to-instantiate-class-itk-realtohalfhermitianforwardfftimagefilter-class-itk-image-double-3-class-itk-image-class-std-complex-double-3/5865/3 "2023-04-21T09:47:53Z")

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I have get this error。。。。。

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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, 6:06am UTC](https://discourse.itk.org/t/description-itk-error-object-factory-failed-to-instantiate-class-itk-realtohalfhermitianforwardfftimagefilter-class-itk-image-double-3-class-itk-image-class-std-complex-double-3/5865/4 "2024-03-18T06:06:57Z")

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after recompiling what?do you use ITK5.4? i find that in ITK5.4 RTK is part of ITK,More precisely，RTK is a Module of ITK,so maybe there is no need to compile RTK,and i compiled ITK,the same error as you mentioned occurs,could you please tell me you solution,thank you!