Merge pull request #24233 from jvuillaumier:rotate_flip_hal_hooks

Add HAL implementation hooks to cv::flip() and cv::rotate() functions from core module #24233

Hello,

This change proposes the addition of HAL hooks for cv::flip() and cv::rotate() functions from OpenCV core module.
Flip and rotation are functions commonly available from 2D hardware accelerators. This is convenient provision to enable custom optimized implementation of image flip/rotation on systems embedding such accelerator.

Thank you

### Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

- [x] I agree to contribute to the project under Apache 2 License.
- [x] To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
- [x] The PR is proposed to the proper branch
- [ ] There is a reference to the original bug report and related work
- [ ] There is accuracy test, performance test and test data in opencv_extra repository, if applicable
      Patch to opencv_extra has the same branch name.
- [ ] The feature is well documented and sample code can be built with the project CMake

modules/core/src/hal_replacement.hpp

@@ -731,6 +731,47 @@ inline int hal_ni_minMaxIdx(const uchar* src_data, size_t src_step, int width, i
 #define cv_hal_minMaxIdx hal_ni_minMaxIdx
 //! @endcond
 
+/**
+   @brief hal_flip
+   @param src_type source and destination image type
+   @param src_data source image data
+   @param src_step source image step
+   @param src_width source and destination image width
+   @param src_height source and destination image height
+   @param dst_data destination image data
+   @param dst_step destination image step
+   @param flip_mode 0 flips around x-axis, positive around y-axis, negative both
+ */
+inline int hal_ni_flip(int src_type, const uchar* src_data, size_t src_step, int src_width, int src_height,
+                       uchar* dst_data, size_t dst_step, int flip_mode) { return CV_HAL_ERROR_NOT_IMPLEMENTED; }
+
+//! @cond IGNORED
+#define cv_hal_flip hal_ni_flip
+//! @endcond
+
+
+/**
+   @brief rotate90
+   @param src_type source and destination image type
+   @param src_data source image data
+   @param src_step source image step
+   @param src_width source image width
+   If angle has value [180] it is also destination image width
+   If angle has values [90, 270] it is also destination image height
+   @param src_height source and destination image height (destination image width for angles [90, 270])
+   If angle has value [180] it is also destination image height
+   If angle has values [90, 270] it is also destination image width
+   @param dst_data destination image data
+   @param dst_step destination image step
+   @param angle clockwise angle for rotation in degrees from set [90, 180, 270]
+ */
+inline int hal_ni_rotate90(int src_type, const uchar* src_data, size_t src_step, int src_width, int src_height,
+                           uchar* dst_data, size_t dst_step, int angle) { return CV_HAL_ERROR_NOT_IMPLEMENTED; }
+
+//! @cond IGNORED
+#define cv_hal_rotate90 hal_ni_rotate90
+//! @endcond
+
 //! @}
 
 

modules/core/src/matrix_transform.cpp

@@ -4,6 +4,7 @@
 
 #include "precomp.hpp"
 #include "opencl_kernels_core.hpp"
+#include "hal_replacement.hpp"
 #include "opencv2/core/detail/dispatch_helper.impl.hpp"
 
 #include <algorithm> // std::swap_ranges
@@ -802,6 +803,9 @@ void flip( InputArray _src, OutputArray _dst, int flip_mode )
     _dst.create( size, type );
     Mat dst = _dst.getMat();
 
+    CALL_HAL(flip, cv_hal_flip, type, src.ptr(), src.step, src.cols, src.rows,
+             dst.ptr(), dst.step, flip_mode);
+
     CV_IPP_RUN_FAST(ipp_flip(src, dst, flip_mode));
 
     size_t esz = CV_ELEM_SIZE(type);
@@ -1075,10 +1079,8 @@ void broadcast(InputArray _src, InputArray _shape, OutputArray _dst) {
     }
 }
 
-void rotate(InputArray _src, OutputArray _dst, int rotateMode)
+static void rotateImpl(InputArray _src, OutputArray _dst, int rotateMode)
 {
-    CV_Assert(_src.dims() <= 2);
-
     switch (rotateMode)
     {
     case ROTATE_90_CLOCKWISE:
@@ -1097,4 +1099,51 @@ void rotate(InputArray _src, OutputArray _dst, int rotateMode)
     }
 }
 
+void rotate(InputArray _src, OutputArray _dst, int rotateMode)
+{
+    CV_Assert(_src.dims() <= 2);
+    int angle;
+
+    if (_dst.isUMat())
+    {
+        rotateImpl(_src, _dst, rotateMode);
+        return;
+    }
+
+    Mat src = _src.getMat();
+    int type = src.type();
+    if( src.empty() )
+    {
+        _dst.release();
+        return;
+    }
+
+    switch (rotateMode)
+    {
+    case ROTATE_90_CLOCKWISE:
+        _dst.create(src.cols, src.rows, type);
+        angle = 90;
+        break;
+    case ROTATE_180:
+        _dst.create(src.rows, src.cols, type);
+        angle = 180;
+        break;
+    case ROTATE_90_COUNTERCLOCKWISE:
+        _dst.create(src.cols, src.rows, type);
+        angle = 270;
+        break;
+    default:
+        _dst.create(src.rows, src.cols, type);
+        angle = 0;
+        break;
+    }
+
+    Mat dst = _dst.getMat();
+    CALL_HAL(rotate90, cv_hal_rotate90, type, src.ptr(), src.step, src.cols, src.rows,
+             dst.ptr(), dst.step, angle);
+
+    // use src (Mat) since _src (InputArray) is updated by _dst.create() when in-place
+    rotateImpl(src, _dst, rotateMode);
+}
+
 }  // namespace