# Where is the real implementation of cv\_hal\_dft2D?

**URL:** <https://forum.opencv.org/t/where-is-the-real-implementation-of-cv-hal-dft2d/12534>\
**Category:** C++\
**Created:** [March 26, 2023, 10:26am UTC](https://forum.opencv.org/t/where-is-the-real-implementation-of-cv-hal-dft2d/12534 "2023-03-26T10:26:44Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![Yongqiang\_Li](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.opencv.org/yongqiang_li/32/3886_2.png) [@Yongqiang\_Li](https://forum.opencv.org/u/Yongqiang_Li)\
**Post date:** [March 26, 2023, 10:26am UTC](https://forum.opencv.org/t/where-is-the-real-implementation-of-cv-hal-dft2d/12534/1 "2023-03-26T10:26:44Z")

</div>

Dear all,

I am reading OpenCV 4 source code related to template matching. I found internally it will call `cv_hal_dft2D`. But it points to a fake implementation in `modules/core/src/hal_replacement.hpp`.

```auto
inline int hal_ni_dft2D(cvhalDFT *context, const uchar *src_data, size_t src_step, uchar *dst_data, size_t dst_step) { return CV_HAL_ERROR_NOT_IMPLEMENTED; }
#define cv_hal_dft2D hal_ni_dft2D

```

Could anyone help to find where the real implementation is? Or for now, there has no HAL version for `dft2D`?

Thanks a lot!

Regards,  
Yongqiang