created wrappers for new NPP functions

removed void integral(const GpuMat& src, GpuMat& sum, GpuMat& sqsum, Stream& stream) - it fails with NPP_NOT_IMPLEMENTED error
updated docs, accuracy and performance tests

samples/gpu/alpha_comp.cpp

@@ -0,0 +1,68 @@
+#include <iostream>
+
+#include "opencv2/core/opengl_interop.hpp"
+#include "opencv2/highgui/highgui.hpp"
+#include "opencv2/gpu/gpu.hpp"
+
+using namespace std;
+using namespace cv;
+using namespace cv::gpu;
+
+int main()
+{
+    cout << "This program demonstrates using alphaComp" << endl;
+    cout << "Press SPACE to change compositing operation" << endl;
+    cout << "Press ESC to exit" << endl;
+
+    namedWindow("First Image", WINDOW_NORMAL);
+    namedWindow("Second Image", WINDOW_NORMAL);
+    namedWindow("Result", WINDOW_OPENGL);
+
+    setGlDevice();
+
+    Mat src1(640, 480, CV_8UC4, Scalar::all(0));
+    Mat src2(640, 480, CV_8UC4, Scalar::all(0));
+
+    rectangle(src1, Rect(50, 50, 200, 200), Scalar(0, 0, 255, 128), 30);
+    rectangle(src2, Rect(100, 100, 200, 200), Scalar(255, 0, 0, 128), 30);
+
+    GpuMat d_src1(src1);
+    GpuMat d_src2(src2);
+
+    GpuMat d_res;
+
+    imshow("First Image", src1);
+    imshow("Second Image", src2);
+
+    int alpha_op = ALPHA_OVER;
+
+    const char* op_names[] = 
+    { 
+        "ALPHA_OVER", "ALPHA_IN", "ALPHA_OUT", "ALPHA_ATOP", "ALPHA_XOR", "ALPHA_PLUS", "ALPHA_OVER_PREMUL", "ALPHA_IN_PREMUL", "ALPHA_OUT_PREMUL",
+        "ALPHA_ATOP_PREMUL", "ALPHA_XOR_PREMUL", "ALPHA_PLUS_PREMUL", "ALPHA_PREMUL"
+    };
+
+    while (true)
+    {
+        cout << op_names[alpha_op] << endl;
+
+        alphaComp(d_src1, d_src2, d_res, alpha_op);
+
+        imshow("Result", d_res);
+
+        char key = static_cast<char>(waitKey());
+
+        if (key == 27)
+            break;
+
+        if (key == 32)
+        {
+            ++alpha_op;
+
+            if (alpha_op > ALPHA_PREMUL)
+                alpha_op = ALPHA_OVER; 
+        }
+    }
+
+    return 0;
+}

samples/gpu/brox_optical_flow.cpp

@@ -226,7 +226,7 @@ int main(int argc, const char* argv[])
                 break;
 
             case 'S':
-                if (currentFrame < frames.size() - 1)
+                if (currentFrame < static_cast<int>(frames.size()) - 1)
                     ++currentFrame;
 
                 imshow("Interpolated frame", frames[currentFrame]);

samples/gpu/farneback_optical_flow.cpp

@@ -26,7 +26,7 @@ void colorizeFlow(const Mat &u, const Mat &v, Mat &dst)
     minMaxLoc(v, &vMin, &vMax, 0, 0);
     uMin = ::abs(uMin); uMax = ::abs(uMax);
     vMin = ::abs(vMin); vMax = ::abs(vMax);
-    float dMax = ::max(::max(uMin, uMax), ::max(vMin, vMax));
+    float dMax = static_cast<float>(::max(::max(uMin, uMax), ::max(vMin, vMax)));
 
     dst.create(u.size(), CV_8UC3);
     for (int y = 0; y < u.rows; ++y)
@@ -111,11 +111,11 @@ int main(int argc, char **argv)
 
         s.str("");
         s << "opt. flow FPS: " << cvRound((getTickFrequency()/(tc1-tc0)));
-        putText(image, s.str(), Point(5, 65), FONT_HERSHEY_SIMPLEX, 1., Scalar(255,0,255), 2.);
+        putText(image, s.str(), Point(5, 65), FONT_HERSHEY_SIMPLEX, 1., Scalar(255,0,255), 2);
 
         s.str("");
         s << "total FPS: " << cvRound((getTickFrequency()/(t1-t0)));
-        putText(image, s.str(), Point(5, 105), FONT_HERSHEY_SIMPLEX, 1., Scalar(255,0,255), 2.);
+        putText(image, s.str(), Point(5, 105), FONT_HERSHEY_SIMPLEX, 1., Scalar(255,0,255), 2);
 
         imshow("flow", image);
 

samples/gpu/performance/performance.cpp

@@ -63,7 +63,7 @@ void TestSystem::finishCurrentSubtest()
     double cpu_time = cpu_elapsed_ / getTickFrequency() * 1000.0;
     double gpu_time = gpu_elapsed_ / getTickFrequency() * 1000.0;
 
-    double speedup = static_cast<double>(cpu_elapsed_) / std::max((int64)1, gpu_elapsed_);
+    double speedup = static_cast<double>(cpu_elapsed_) / std::max(1.0, gpu_elapsed_);
     speedup_total_ += speedup;
 
     printMetrics(cpu_time, gpu_time, speedup);

samples/gpu/performance/performance.h

@@ -127,8 +127,10 @@ private:
     std::stringstream cur_subtest_description_;
     bool cur_subtest_is_empty_;
 
-    int64 cpu_started_, cpu_elapsed_;
-    int64 gpu_started_, gpu_elapsed_;
+    int64 cpu_started_;
+    int64 gpu_started_;
+    double cpu_elapsed_;
+    double gpu_elapsed_;
 
     double speedup_total_;
     int num_subtests_called_;

samples/gpu/performance/tests.cpp

@@ -1199,7 +1199,7 @@ TEST(FarnebackOpticalFlow)
     if (frame1.empty()) throw runtime_error("can't open " + datasets[i] + "2.png");
 
     gpu::FarnebackOpticalFlow calc;
-    calc.fastPyramids = fastPyramids;
+    calc.fastPyramids = fastPyramids != 0;
     calc.flags |= useGaussianBlur ? OPTFLOW_FARNEBACK_GAUSSIAN : 0;
 
     gpu::GpuMat d_frame0(frame0), d_frame1(frame1), d_flowx, d_flowy;