From a57030a0cda4a144c1b800ce5e7efb6c127aa571 Mon Sep 17 00:00:00 2001
From: Ilya Lavrenov <ilya.lavrenov@itseez.com>
Date: Sat, 9 Nov 2013 17:03:30 +0400
Subject: [PATCH] added YCrCb to RGB, BGR, RGBA, BGRA modes to ocl::cvtColor

---
 modules/ocl/src/color.cpp           | 28 +++++++++++++++++++--
 modules/ocl/src/opencl/cvt_color.cl | 38 +++++++++++++++++++++++++++++
 modules/ocl/test/test_color.cpp     | 32 ++++++++++++------------
 3 files changed, 80 insertions(+), 18 deletions(-)

diff --git a/modules/ocl/src/color.cpp b/modules/ocl/src/color.cpp
index 766e992dd1..b25b71feee 100644
--- a/modules/ocl/src/color.cpp
+++ b/modules/ocl/src/color.cpp
@@ -162,6 +162,30 @@ static void YUV2RGB_NV12_caller(const oclMat &src, oclMat &dst, int bidx)
     openCLExecuteKernel(src.clCxt, &cvt_color, "YUV2RGBA_NV12", gt, lt, args, -1, -1, build_options.c_str());
 }
 
+static void YCrCb2RGB_caller(const oclMat &src, oclMat &dst, int bidx)
+{
+    int channels = dst.channels();
+    int src_offset = src.offset / src.elemSize1(), src_step = src.step1();
+    int dst_offset = dst.offset / dst.elemSize1(), dst_step = dst.step1();
+
+    std::string buildOptions = format("-D DEPTH_%d", src.depth());
+
+    vector<pair<size_t , const void *> > args;
+    args.push_back( make_pair( sizeof(cl_int) , (void *)&src.cols));
+    args.push_back( make_pair( sizeof(cl_int) , (void *)&src.rows));
+    args.push_back( make_pair( sizeof(cl_int) , (void *)&src_step));
+    args.push_back( make_pair( sizeof(cl_int) , (void *)&dst_step));
+    args.push_back( make_pair( sizeof(cl_int) , (void *)&channels));
+    args.push_back( make_pair( sizeof(cl_int) , (void *)&bidx));
+    args.push_back( make_pair( sizeof(cl_mem) , (void *)&src.data));
+    args.push_back( make_pair( sizeof(cl_mem) , (void *)&dst.data));
+    args.push_back( make_pair( sizeof(cl_int) , (void *)&src_offset ));
+    args.push_back( make_pair( sizeof(cl_int) , (void *)&dst_offset ));
+
+    size_t gt[3] = { src.cols, src.rows, 1 }, lt[3] = { 16, 16, 1 };
+    openCLExecuteKernel(src.clCxt, &cvt_color, "YCrCb2RGB", gt, lt, args, -1, -1, buildOptions.c_str());
+}
+
 static void RGB2YCrCb_caller(const oclMat &src, oclMat &dst, int bidx)
 {
     std::string build_options = format("-D DEPTH_%d", src.depth());
@@ -270,9 +294,9 @@ static void cvtColor_caller(const oclMat &src, oclMat &dst, int code, int dcn)
         if( dcn <= 0 )
             dcn = 3;
         CV_Assert(scn == 3 && (dcn == 3 || dcn == 4));
-        bidx = code == CV_YCrCb2RGB ? 0 : 2;
+        bidx = code == CV_YCrCb2BGR ? 0 : 2;
         dst.create(sz, CV_MAKETYPE(depth, dcn));
-//        YUV2RGB_caller(src, dst, bidx);
+        YCrCb2RGB_caller(src, dst, bidx);
         break;
     }
     /*
diff --git a/modules/ocl/src/opencl/cvt_color.cl b/modules/ocl/src/opencl/cvt_color.cl
index 2ba7739c22..de53da52ee 100644
--- a/modules/ocl/src/opencl/cvt_color.cl
+++ b/modules/ocl/src/opencl/cvt_color.cl
@@ -293,3 +293,41 @@ __kernel void RGB2YCrCb(int cols, int rows, int src_step, int dst_step,
         dst[dst_idx + 2] = SAT_CAST( Cb );
     }
 }
+
+__constant float c_YCrCb2RGBCoeffs_f[4] = { 1.403f, -0.714f, -0.344f, 1.773f };
+__constant int   c_YCrCb2RGBCoeffs_i[4] = { 22987, -11698, -5636, 29049 };
+
+__kernel void YCrCb2RGB(int cols, int rows, int src_step, int dst_step, int channels,
+                        int bidx, __global const DATA_TYPE* src, __global DATA_TYPE* dst,
+                        int src_offset, int dst_offset)
+{
+    int x = get_global_id(0);
+    int y = get_global_id(1);
+
+    if (y < rows && x < cols)
+    {
+        x <<= 2;
+        int src_idx = mad24(y, src_step, src_offset + x);
+        int dst_idx = mad24(y, dst_step, dst_offset + x);
+
+        DATA_TYPE ycrcb[] = { src[src_idx], src[src_idx + 1], src[src_idx + 2] };
+
+#ifdef DEPTH_5
+        __constant float * coeff = c_YCrCb2RGBCoeffs_f;
+        float r = ycrcb[0] + coeff[0] * (ycrcb[1] - HALF_MAX);
+        float g = ycrcb[0] + coeff[1] * (ycrcb[1] - HALF_MAX) + coeff[2] * (ycrcb[2] - HALF_MAX);
+        float b = ycrcb[0] + coeff[3] * (ycrcb[2] - HALF_MAX);
+#else
+        __constant int * coeff = c_YCrCb2RGBCoeffs_i;
+        int r = ycrcb[0] + CV_DESCALE(coeff[0] * (ycrcb[1] - HALF_MAX), yuv_shift);
+        int g = ycrcb[0] + CV_DESCALE(coeff[1] * (ycrcb[1] - HALF_MAX) + coeff[2] * (ycrcb[2] - HALF_MAX), yuv_shift);
+        int b = ycrcb[0] + CV_DESCALE(coeff[3] * (ycrcb[2] - HALF_MAX), yuv_shift);
+#endif
+
+        dst[dst_idx + (bidx^2)] = SAT_CAST(r);
+        dst[dst_idx + 1] = SAT_CAST(g);
+        dst[dst_idx + bidx] = SAT_CAST(b);
+        if (channels == 4)
+            dst[dst_idx + 3] = MAX_NUM;
+    }
+}
diff --git a/modules/ocl/test/test_color.cpp b/modules/ocl/test/test_color.cpp
index f5f9f43177..b2f5c6fb2d 100644
--- a/modules/ocl/test/test_color.cpp
+++ b/modules/ocl/test/test_color.cpp
@@ -203,22 +203,22 @@ OCL_TEST_P(CvtColor, BGRA2YCrCb)
 {
     doTest(4, 3, CVTCODE(BGR2YCrCb));
 }
-//OCL_TEST_P(CvtColor, YCrCb2RGB)
-//{
-//    doTest(3, 3, CVTCODE(YCrCb2RGB));
-//}
-//OCL_TEST_P(CvtColor, YCrCb2BGR)
-//{
-//    doTest(3, 3, CVTCODE(YCrCb2BGR));
-//}
-//OCL_TEST_P(CvtColor, YCrCb2RGBA)
-//{
-//    doTest(3, 4, CVTCODE(YCrCb2RGB));
-//}
-//OCL_TEST_P(CvtColor, YCrCb2BGRA)
-//{
-//    doTest(3, 4, CVTCODE(YCrCb2BGR));
-//}
+OCL_TEST_P(CvtColor, YCrCb2RGB)
+{
+    doTest(3, 3, CVTCODE(YCrCb2RGB));
+}
+OCL_TEST_P(CvtColor, YCrCb2BGR)
+{
+    doTest(3, 3, CVTCODE(YCrCb2BGR));
+}
+OCL_TEST_P(CvtColor, YCrCb2RGBA)
+{
+    doTest(3, 4, CVTCODE(YCrCb2RGB));
+}
+OCL_TEST_P(CvtColor, YCrCb2BGRA)
+{
+    doTest(3, 4, CVTCODE(YCrCb2BGR));
+}
 
 struct CvtColor_YUV420 :
         public CvtColor