converted some OpenCV C samples to C++

samples/cpp/laplace.cpp

@@ -0,0 +1,60 @@
+#include "opencv2/highgui/highgui.hpp"
+#include "opencv2/imgproc/imgproc.hpp"
+
+#include <ctype.h>
+#include <iostream>
+
+using namespace cv;
+using namespace std;
+
+int sigma = 3;
+int smoothType = CV_GAUSSIAN;
+
+int main( int argc, char** argv )
+{
+    VideoCapture cap;
+
+    if( argc == 1 || (argc == 2 && strlen(argv[1]) == 1 && isdigit(argv[1][0])))
+        cap.open(argc == 2 ? argv[1][0] - '0' : 0);
+    else if( argc == 2 )
+        cap.open(argv[1]);
+
+    if( !cap.isOpened() )
+    {
+        cout << "Could not initialize capturing...\n";
+        return -1;
+    }
+
+    namedWindow( "Laplacian", 0 );
+    createTrackbar( "Sigma", "Laplacian", &sigma, 15, 0 );
+
+    Mat smoothed, laplace, result;
+    
+    for(;;)
+    {
+        Mat frame;
+        cap >> frame;
+        if( frame.empty() )
+            break;
+
+        int ksize = (sigma*5)|1;
+        if(smoothType == CV_GAUSSIAN)
+            GaussianBlur(frame, smoothed, Size(ksize, ksize), sigma, sigma);
+        else if(smoothType == CV_BLUR)
+            blur(frame, smoothed, Size(ksize, ksize));
+        else
+            medianBlur(frame, smoothed, ksize);
+        
+        Laplacian(smoothed, laplace, CV_16S, 5);
+        convertScaleAbs(laplace, result, (sigma+1)*0.25);
+        imshow("Laplacian", result);
+
+        int c = waitKey(30);
+        if( c == ' ' )
+            smoothType = smoothType == CV_GAUSSIAN ? CV_BLUR : smoothType == CV_BLUR ? CV_MEDIAN : CV_GAUSSIAN;
+        if( c == 'q' || c == 'Q' || (c & 255) == 27 )
+            break;
+    }
+
+    return 0;
+}