initial commit

samples/cpp/laplace.cpp

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+#include "opencv2/videoio.hpp"
+#include "opencv2/highgui.hpp"
+#include "opencv2/imgproc.hpp"
+
+#include <ctype.h>
+#include <stdio.h>
+#include <iostream>
+
+using namespace cv;
+using namespace std;
+
+static void help()
+{
+    cout <<
+            "\nThis program demonstrates Laplace point/edge detection using OpenCV function Laplacian()\n"
+            "It captures from the camera of your choice: 0, 1, ... default 0\n"
+            "Call:\n"
+            "./laplace -c=<camera #, default 0> -p=<index of the frame to be decoded/captured next>\n" << endl;
+}
+
+enum {GAUSSIAN, BLUR, MEDIAN};
+
+int sigma = 3;
+int smoothType = GAUSSIAN;
+
+int main( int argc, char** argv )
+{
+    cv::CommandLineParser parser(argc, argv, "{ c | 0 | }{ p | | }");
+    help();
+
+    VideoCapture cap;
+    string camera = parser.get<string>("c");
+    if (camera.size() == 1 && isdigit(camera[0]))
+        cap.open(parser.get<int>("c"));
+    else
+        cap.open(samples::findFileOrKeep(camera));
+    if (!cap.isOpened())
+    {
+        cerr << "Can't open camera/video stream: " << camera << endl;
+        return 1;
+    }
+    cout << "Video " << parser.get<string>("c") <<
+        ": width=" << cap.get(CAP_PROP_FRAME_WIDTH) <<
+        ", height=" << cap.get(CAP_PROP_FRAME_HEIGHT) <<
+        ", nframes=" << cap.get(CAP_PROP_FRAME_COUNT) << endl;
+    int pos = 0;
+    if (parser.has("p"))
+    {
+        pos = parser.get<int>("p");
+    }
+    if (!parser.check())
+    {
+        parser.printErrors();
+        return -1;
+    }
+
+    if (pos != 0)
+    {
+        cout << "seeking to frame #" << pos << endl;
+        if (!cap.set(CAP_PROP_POS_FRAMES, pos))
+        {
+            cerr << "ERROR: seekeing is not supported" << endl;
+        }
+    }
+
+    namedWindow("Laplacian", WINDOW_AUTOSIZE);
+    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 == GAUSSIAN)
+            GaussianBlur(frame, smoothed, Size(ksize, ksize), sigma, sigma);
+        else if(smoothType == 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);
+
+        char c = (char)waitKey(30);
+        if( c == ' ' )
+            smoothType = smoothType == GAUSSIAN ? BLUR : smoothType == BLUR ? MEDIAN : GAUSSIAN;
+        if( c == 'q' || c == 'Q' || c == 27 )
+            break;
+    }
+
+    return 0;
+}