louis89's profile - activity

Hi.I use below code for video capture from my webcam:

Mat frame;
int threshval =120;
static void on_trackbar(int, void*)
{


 }
 int main(int argc, char* argv[])
 {

     VideoCapture cap(0);
     if (!cap.isOpened())
     {
         cout << "Cannot open the video cam" << endl;
         return  0;

     }

     while (1)
     {
         bool bSuccess = cap.read(frame); // Khandane yek frame jadid dar video


         if (!bSuccess)
         {
             cout << "Cannot read a frame from video stream" << endl;
             break;
         }
    createTrackbar("Threshold", "Image", &threshval, 255, on_trackbar);
    on_trackbar(threshval, 0);}
             return 0; }

I want to use a function that takes the image from video capture class and convert that frame to a gray level image and use Canny Edge Detector for that image.for this reason I use this function:

int my_cannyEdgeDetector(){

         cvtColor(frame, frame2, COLOR_BGR2GRAY);
         Canny(frame2, frame2, threshval, threshval * 2, 3);}

I know I wrote the wrong function but I'm begginer in opencv and c++ and I want to get pictures from the main function and put it in the my_cannyEdgeDetector function and imshow frame and frame2 in the end of my main function.I have no idea to set input and output for my_cannyEdgeDetector function.Thank you very much if you help me do this

@Volkmar .thanks for your reply.but where should I add your code to my program?another question is that Is not it necess

How to call a function in a main function With OpenCv and C++? Hi.I use below code for video capture from my webcam: Ma

@berak can i display all frame with another way(except video capture)?

@berak can i display all frame with another way(except video capture)?

@berak I want to get image from my webcam .can I use a LOOP for display all frame One by one؟

How to read all frame in a video without use VideoCapture function in opencv? hi.I'm beginner in OpenCV and c++.I use be

How to change OpenCv code in the form Function? Hi.I'm beginner in OpenCv and c++ code.in below you can see my program:

@LBerger thanks for your help. can you help me to definition this code in the form a function?

@sturkmen this is a detection program that I want to use it in a tracking program.

How to change OpenCv code in the form Function ? Hi.I'm beginner in OpenCv and c++ code.in below you can see my program:

How to change OpenCv code in the form Function for use in another program? Hi.I'm beginner in OpenCv and c++ code.in bel

How to change OpenCv code in the form Function for use in another program? Hi.I'm beginner in OpenCv and c++ code.in bel

How to change OpenCv code in the form Function for use in another program? Hi.I'm beginner in OpenCv and c++ code.in bel

How to change OpenCv code in the form Function for use in another program? Hi.I'm beginner in OpenCv and c++ code.in bel

Hi.I use below code for object detection:

static void on_trackbar(int, void*)
{
}
int main(int argc, char* argv[]) 
{
Mat frame;

Mat frame2 ;
VideoCapture cap(0);
if (!cap.isOpened())
{
    cout << "Cannot open the video cam" << endl;
    return  0;

}
namedWindow("Image", 1);
createTrackbar("Threshold", "Image", &threshval, 255, on_trackbar);

while (1)
{
    bool bSuccess = cap.read(frame); // read a new frame from video


    if (!bSuccess)
    {
        cout << "Cannot read a frame from video stream" << endl;
        break;
    }

    cvtColor(frame, frame2, COLOR_BGR2GRAY);
    GaussianBlur(frame2, frame2, Size(5, 5), 0);
    Canny(frame2, frame2, threshval, threshval * 2, 3);
    morphologyEx(frame2, frame2, MORPH_CLOSE, Mat(), Point(-1, -1), 2);
    Mat stat, centroid;
    Mat bw = threshval < 128 ? (frame2< threshval) : (frame2 > threshval);
    Mat labelImage(frame2.size(), CV_32S);
    int nLabels = connectedComponentsWithStats(bw, labelImage, stat, centroid, 8);

    std::vector<Vec3b> colors(nLabels);
    colors[0] = Vec3b(0, 0, 0);//background
    for (int label = 1; label < nLabels; ++label) 
    {
        colors[label] = Vec3b((rand() & 255), (rand() & 255), (rand() & 255));
    }
    Mat dst(frame2.size(), CV_8UC3);
    for (int r = 0; r < dst.rows; ++r) 
    {
        for (int c = 0; c < dst.cols; ++c) 
        {
            int label = labelImage.at<int>(r, c);
            Vec3b &pixel = dst.at<Vec3b>(r, c);
            pixel = colors[label];
        }
    }
    for (int i = 0; i < nLabels; i++)
    {
        if (stat.at<int>(i, CC_STAT_AREA) <80 && stat.at<int>(i, CC_STAT_AREA) >10) 
        {

            cout << "mitter"<<endl;

        }
    }

    imshow("Image", frame2);

    if (waitKey(1) == 27)
    {
        cout << "esc key is pressed by user" << endl;
        break;
    }

}
return 0;

} I want to have a text on window that show "Detection off" and when the condition if (stat.at<int>(i, CC_STAT_AREA) <80 && stat.at<int>(i, CC_STAT_AREA) >10) was fulfilled then the Text in the window change to "Detection On".I'm beginner in OpenCv and c++ and I have no idea to do this.I'm so grateful to help me do this

Display a Text on the windows with OpenCv and c++ Hi.I use below code for object detection: static void on_trackbar(in

@Ziri I have two text:1-"Detection OFF" 2-"Detection ON".I want to displayed only "Detection ON" if the condition is tru

@LBerger this program only show" mitter" if stat.at<int>(i, CC_STAT_AREA) <80....but I want to change the text

@Ziri no.I try this but "Detection off" still exist when the condition was fulfilled.

@Ziri yes.in this way I have two Text,that "Detection Off" is Always in the picture and "Detection On" while the condi

yes.in this way I have two Text,that "Detection Off" is Always in the picture and "Detection On" while the condition w

@Ziri but how?can you show me?I want to have a text on frame that show "Detection off" and when the condition if (stat.a

but how?can you show me?I want to have a text on frame that show "Detection off" and when the condition if (stat.at<i

@Ziri can I change text after a condition?

@LBerger thanks for your reply.This program works well for monochrome object, but it does not work well for an object

@LBerger thanks for your reply.This program works well for monochrome object, but it does not work well (for example, o

@LBerger thanks for your reply.This program works well for monochrome, but it does not work well (for example, only the

Display a Text on the windows with OpenCv and c++ Hi.I use below code for object detection: Mat frame; cv::Mat frame

I solve it.the problem was #include <opencv2\opencv.hpp>

yes.I do this.I use cmake for build opencv3.3_rc and Without receiving any errors I succeeded to build it in visual studio 2015.I use this version of opencv for another program(for example connected component) but when I use your code in this version of opencv,my program stops without getting any errors

yes.your program works very well in opencv2.4.13 but when I use this program in opencv3.0.0 or opencv3.3_rc I'm having trouble hanging up the computer

I am using OpenCV for a C++ application.I have a fixed rectangle in my image.I want when I click on the mouse on the rectangle,than The rectangle position changes to where the mouse is released.I'm beginner in opencv and c++.do you have any idea to do this?this is my code:

#include <iostream>
#include <opencv2/core/core.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/highgui/highgui.hpp>

using namespace cv;
using namespace std;

int main()
{
// Open the video file
VideoCapture capture("blowcontrast1.avi");

if (!capture.isOpened())
    return 1;

bool stop(false);
Mat frame; //current video frame
namedWindow("Extracted Frame");
int delay = 1;

cout << capture.get(CV_CAP_PROP_FPS);
capture.set(CV_CAP_PROP_POS_AVI_RATIO, 0.5);

while (!stop)
{
    if (!capture.read(frame))
        break;
            Rect rectangle(200 , 150, 40, 40);
            rectangle(frame, rectangle, Scalar(255, 255, 255));
    imshow("Extracted Frame", frame);

    if (waitKey(delay) >= 0)
        stop = true;
}

waitKey();
}