Merge pull request #13206 from elatkin:el/gapi_perf_rgb2lab

GAPI (fluid): RGB to Lab optimization (#13206)

* GAPI (fluid): BGR2LUV, RGB2Lab: performance test

* GAPI (fluid): BGR2LUV, RGB2Lab: using cv::hal::cvtBGRtoLab

* GAPI (fluid): BGR2LUV, RGB2Lab: hide reference code with #ifdef

modules/gapi/perf/common/gapi_imgproc_perf_tests_inl.hpp

@@ -754,7 +754,7 @@ PERF_TEST_P_(RGB2LabPerfTest, TestPerformance)
 
     TEST_CYCLE()
     {
-        c.apply(in_mat1, out_mat_gapi, std::move(compile_args));
+        c.apply(in_mat1, out_mat_gapi);
     }
 
     // Comparison //////////////////////////////////////////////////////////////
@@ -792,7 +792,7 @@ PERF_TEST_P_(BGR2LUVPerfTest, TestPerformance)
 
     TEST_CYCLE()
     {
-        c.apply(in_mat1, out_mat_gapi, std::move(compile_args));
+        c.apply(in_mat1, out_mat_gapi);
     }
 
     // Comparison //////////////////////////////////////////////////////////////

modules/gapi/perf/cpu/gapi_imgproc_perf_tests_fluid.cpp

@@ -63,4 +63,14 @@ namespace opencv_test
                 Values(szVGA, sz720p, sz1080p),
                 Values(cv::compile_args(IMGPROC_FLUID))));
 
+    INSTANTIATE_TEST_CASE_P(BGR2LUVPerfTestFluid, BGR2LUVPerfTest,
+        Combine(Values(AbsSimilarPoints(1, 0.05).to_compare_f()),
+                Values(szVGA, sz720p, sz1080p),
+                Values(cv::compile_args(IMGPROC_FLUID))));
+
+    INSTANTIATE_TEST_CASE_P(RGB2LabPerfTestFluid, RGB2LabPerfTest,
+        Combine(Values(AbsSimilarPoints(1, 0.05).to_compare_f()),
+                Values(szVGA, sz720p, sz1080p),
+                Values(cv::compile_args(IMGPROC_FLUID))));
+
 }

modules/gapi/src/backends/fluid/gfluidimgproc.cpp

@@ -27,7 +27,8 @@
 
 #include "gfluidimgproc_func.hpp"
 
-#include <opencv2/core/hal/intrin.hpp>
+#include "opencv2/imgproc/hal/hal.hpp"
+#include "opencv2/core/hal/intrin.hpp"
 
 #include <cmath>
 #include <cstdlib>
@@ -173,6 +174,10 @@ GAPI_FLUID_KERNEL(GFluidYUV2RGB, cv::gapi::imgproc::GYUV2RGB, false)
 
 enum LabLUV { LL_Lab, LL_LUV };
 
+#define LabLuv_reference 0  // 1=use reference code of RGB/BGR to LUV/Lab, 0=don't
+
+#if LabLuv_reference
+
 // gamma-correction (inverse) for sRGB, 1/gamma=2.4 for inverse, like for Mac OS (?)
 static inline float f_gamma(float x)
 {
@@ -230,22 +235,9 @@ static inline void f_xyz2luv(float  X, float  Y, float  Z,
     v = 13*L * (v1 - vn);
 }
 
-// compile-time parameters: output format (Lab/LUV),
-// and position of blue channel in BGR/RGB (0 or 2)
 template<LabLUV labluv, int blue=0>
-static void run_rgb2labluv(Buffer &dst, const View &src)
+static void run_rgb2labluv_reference(uchar out[], const uchar in[], int width)
 {
-    GAPI_Assert(src.meta().depth == CV_8U);
-    GAPI_Assert(dst.meta().depth == CV_8U);
-    GAPI_Assert(src.meta().chan == 3);
-    GAPI_Assert(dst.meta().chan == 3);
-    GAPI_Assert(src.length() == dst.length());
-
-    const auto *in  = src.InLine<uchar>(0);
-          auto *out = dst.OutLine<uchar>();
-
-    int width = dst.length();
-
     for (int w=0; w < width; w++)
     {
         float R, G, B;
@@ -284,6 +276,42 @@ static void run_rgb2labluv(Buffer &dst, const View &src)
     }
 }
 
+#endif  // LabLuv_reference
+
+// compile-time parameters: output format (Lab/LUV),
+// and position of blue channel in BGR/RGB (0 or 2)
+template<LabLUV labluv, int blue=0>
+static void run_rgb2labluv(Buffer &dst, const View &src)
+{
+    GAPI_Assert(src.meta().depth == CV_8U);
+    GAPI_Assert(dst.meta().depth == CV_8U);
+    GAPI_Assert(src.meta().chan == 3);
+    GAPI_Assert(dst.meta().chan == 3);
+    GAPI_Assert(src.length() == dst.length());
+
+    const auto *in  = src.InLine<uchar>(0);
+          auto *out = dst.OutLine<uchar>();
+
+    int width = dst.length();
+
+#if LabLuv_reference
+    run_rgb2labluv_reference<labluv, blue>(out, in, width);
+#else
+    uchar *dst_data = out;
+    const uchar *src_data = in;
+    size_t src_step = width;
+    size_t dst_step = width;
+    int height = 1;
+    int depth = CV_8U;
+    int scn = 3;
+    bool swapBlue = (blue == 2);
+    bool isLab = (LL_Lab == labluv);
+    bool srgb = true;
+    cv::hal::cvtBGRtoLab(src_data, src_step, dst_data, dst_step,
+               width, height, depth, scn, swapBlue, isLab, srgb);
+#endif
+}
+
 GAPI_FLUID_KERNEL(GFluidRGB2Lab, cv::gapi::imgproc::GRGB2Lab, false)
 {
     static const int Window = 1;