Merge pull request opencv#10553 from GlueCrow:bgfg_knn_opencl

Add ocl version BackgroundSubtractorKNN (opencv#10553)

* Add ocl version bgfg_knn

* Add ocl KNN perf test

* ocl KNN: Avoid unnecessary initializing when non-UMat parameters are used

* video: turn off OpenCL for color KNN on Intel devices

due performance degradation

* video: turn off KNN OpenCL on Apple devices with Intel iGPU

due process freeze during clBuildProgram() call

Author: GlueCrow

modules/video/perf/opencl/perf_bgfg_knn.cpp

@@ -0,0 +1,95 @@
+// This file is part of OpenCV project.
+// It is subject to the license terms in the LICENSE file found in the top-level directory
+// of this distribution and at http://opencv.org/license.html.
+
+#include "../perf_precomp.hpp"
+#include "opencv2/ts/ocl_perf.hpp"
+
+#ifdef HAVE_OPENCL
+#ifdef HAVE_VIDEO_INPUT
+#include "../perf_bgfg_utils.hpp"
+
+namespace cvtest {
+namespace ocl {
+
+//////////////////////////// KNN//////////////////////////
+
+typedef tuple<string, int> VideoKNNParamType;
+typedef TestBaseWithParam<VideoKNNParamType> KNN_Apply;
+typedef TestBaseWithParam<VideoKNNParamType> KNN_GetBackgroundImage;
+
+using namespace opencv_test;
+
+OCL_PERF_TEST_P(KNN_Apply, KNN, Combine(Values("gpu/video/768x576.avi", "gpu/video/1920x1080.avi"), Values(1,3)))
+{
+    VideoKNNParamType params = GetParam();
+
+    const string inputFile = getDataPath(get<0>(params));
+
+    const int cn = get<1>(params);
+    int nFrame = 5;
+
+    vector<Mat> frame_buffer(nFrame);
+
+    cv::VideoCapture cap(inputFile);
+    ASSERT_TRUE(cap.isOpened());
+    prepareData(cap, cn, frame_buffer);
+
+    UMat u_foreground;
+
+    OCL_TEST_CYCLE()
+    {
+        Ptr<cv::BackgroundSubtractorKNN> knn = createBackgroundSubtractorKNN();
+        knn->setDetectShadows(false);
+        u_foreground.release();
+        for (int i = 0; i < nFrame; i++)
+        {
+            knn->apply(frame_buffer[i], u_foreground);
+        }
+    }
+    SANITY_CHECK_NOTHING();
+}
+
+OCL_PERF_TEST_P(KNN_GetBackgroundImage, KNN, Values(
+        std::make_pair<string, int>("gpu/video/768x576.avi", 5),
+        std::make_pair<string, int>("gpu/video/1920x1080.avi", 5)))
+{
+    VideoKNNParamType params = GetParam();
+
+    const string inputFile = getDataPath(get<0>(params));
+
+    const int cn = 3;
+    const int skipFrames = get<1>(params);
+    int nFrame = 10;
+
+    vector<Mat> frame_buffer(nFrame);
+
+    cv::VideoCapture cap(inputFile);
+    ASSERT_TRUE(cap.isOpened());
+    prepareData(cap, cn, frame_buffer, skipFrames);
+
+    UMat u_foreground, u_background;
+
+    OCL_TEST_CYCLE()
+    {
+        Ptr<cv::BackgroundSubtractorKNN> knn = createBackgroundSubtractorKNN();
+        knn->setDetectShadows(false);
+        u_foreground.release();
+        u_background.release();
+        for (int i = 0; i < nFrame; i++)
+        {
+            knn->apply(frame_buffer[i], u_foreground);
+        }
+        knn->getBackgroundImage(u_background);
+    }
+#ifdef DEBUG_BGFG
+    imwrite(format("fg_%d_%d_knn_ocl.png", frame_buffer[0].rows, cn), u_foreground.getMat(ACCESS_READ));
+    imwrite(format("bg_%d_%d_knn_ocl.png", frame_buffer[0].rows, cn), u_background.getMat(ACCESS_READ));
+#endif
+    SANITY_CHECK_NOTHING();
+}
+
+}}// namespace cvtest::ocl
+
+#endif
+#endif