OpenCV not working correctly on mac

问题:

I have a program that uses OpenCV to take a picture using your webcam. It works like a charm on windows, yet, it doesn't work on OSx. The Frame where the Webcam view should appear stays empty. And when I take a picture, it just shows a black void, as if it couldnt find the webcam

public void run(){
        try {
            grabber = new VideoInputFrameGrabber(0); 
            grabber.start();
            while (active) {
                IplImage originalImage = grabber.grab();
                Label.setIcon(new ImageIcon( originalImage.getBufferedImage() ));
            }
            grabber.stop();
            grabber.flush();

        } catch (Exception ex) {
            //Logger.getLogger(ChPanel.class.getName()).log(Leve l.SEVERE, null, ex);
        }

    }

    public BufferedImage saveImage(){
        IplImage img;
        try {
            //capture image
            img = grabber.grab();
            // save to file
            File outputfile = new File(Project.getInstance().getFileURLStr() + " capture" + fotoCount++ + ".jpg");
            ImageIO.write(img.getBufferedImage(), "jpg", outputfile);    

            //get file and set it in the project library
            BufferedImage ImportFile = ImageIO.read(outputfile);
            Project p = Project.getInstance();
            MainScreen ms = MainScreen.getInstance();
            ImageIcon takenPhoto = new ImageIcon(ImportFile);
            p.setNextImage(takenPhoto);
            ms.setPanels();
            return ImportFile;
        } catch (com.googlecode.javacv.FrameGrabber.Exception e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;

    }

Does anyone know how to solve this? I suspect something about rights to use the webcam or something like that

回答1:

grabber = new VideoInputFrameGrabber(0); 

Here 0 is specified for Capture device number 0

May be the number 0th device is not available for video capture

Use this code to get the list of devices and number respectively.

import com.googlecode.javacv.cpp.videoInputLib.videoInput;
class Main {


     public static void main(String[] args) {
           int n=videoInput.listDevices();
           for(int i=0;i<n;i++)
        {
            System.out.println(i+" = "+videoInput.getDeviceName(i));

        }

}
}

And then specify the number for that device

grabber = new VideoInputFrameGrabber(1); // 0 or 1 or 2

回答2:

To interact with webcam I use this library webcam-capture you can easely add openCV dependency with maven. This is a great library