From 5bd64e09a360e9fa342fbd951a3635f065bc478e Mon Sep 17 00:00:00 2001
From: Rostislav Vasilikhin <savuor@gmail.com>
Date: Wed, 8 May 2024 16:45:08 +0200
Subject: [PATCH] Merge pull request #25554 from savuor:rv/hal_lut

Merge pull request #25554 from savuor:rv/hal_lut

HAL for LUT added #25554

### 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
- [x] There is a reference to the original bug report and related work
- [x] There is accuracy test, performance test and test data in opencv_extra repository, if applicable
      Patch to opencv_extra has the same branch name.
- [x] The feature is well documented and sample code can be built with the project CMake
---
 modules/core/src/hal_replacement.hpp | 26 ++++++++++++++++++++++++++
 modules/core/src/lut.cpp             |  3 +++
 2 files changed, 29 insertions(+)

diff --git a/modules/core/src/hal_replacement.hpp b/modules/core/src/hal_replacement.hpp
index 498cd63700..bbdfc1e180 100644
--- a/modules/core/src/hal_replacement.hpp
+++ b/modules/core/src/hal_replacement.hpp
@@ -214,6 +214,32 @@ inline int hal_ni_not8u(const uchar *src_data, size_t src_step, uchar *dst_data,
 #define cv_hal_not8u hal_ni_not8u
 //! @endcond
 
+/**
+Lookup table replacement
+Table consists of 256 elements of a size from 1 to 8 bytes having 1 channel or src_channels
+For 8s input type 128 is added to LUT index
+Destination should have the same element type and number of channels as lookup table elements
+@param src_data Source image data
+@param src_step Source image step
+@param src_type Sorce image type
+@param lut_data Pointer to lookup table
+@param lut_channel_size Size of each channel in bytes
+@param lut_channels Number of channels in lookup table
+@param dst_data Destination data
+@param dst_step Destination step
+@param width Width of images
+@param height Height of images
+@sa LUT
+*/
+//! @addtogroup core_hal_interface_lut Lookup table
+//! @{
+inline int hal_ni_lut(const uchar *src_data, size_t src_step, size_t src_type, const uchar* lut_data, size_t lut_channel_size, size_t lut_channels, uchar *dst_data, size_t dst_step, int width, int height) { return CV_HAL_ERROR_NOT_IMPLEMENTED; }
+//! @}
+
+//! @cond IGNORED
+#define cv_hal_lut hal_ni_lut
+//! @endcond
+
 /**
 Hamming norm of a vector
 @param a pointer to vector data
diff --git a/modules/core/src/lut.cpp b/modules/core/src/lut.cpp
index f5dc205082..cb2b9e7b56 100644
--- a/modules/core/src/lut.cpp
+++ b/modules/core/src/lut.cpp
@@ -377,6 +377,9 @@ void cv::LUT( InputArray _src, InputArray _lut, OutputArray _dst )
     CV_OVX_RUN(!ovx::skipSmallImages<VX_KERNEL_TABLE_LOOKUP>(src.cols, src.rows),
                openvx_LUT(src, dst, lut))
 
+    CALL_HAL(LUT, cv_hal_lut, src.data, src.step, src.type(), lut.data,
+             lut.elemSize1(), lutcn, dst.data, dst.step, src.rows, src.cols);
+
 #if !IPP_DISABLE_PERF_LUT
     CV_IPP_RUN(_src.dims() <= 2, ipp_lut(src, lut, dst));
 #endif