Beginning Vision Processing

[NullException33]

So where would you suggest starting with this sample of code. More specifically which object could I use in this sample code to retrieve a live image from and begin processing? I am having trouble determining how to retrieve the live image.

Also when generating code from GRIP did it look anything like this sample?

Thank you for your suggestions!


import edu.wpi.cscore.AxisCamera;
import edu.wpi.cscore.CvSink;
import edu.wpi.cscore.CvSource;
import edu.wpi.first.wpilibj.CameraServer;
import edu.wpi.first.wpilibj.IterativeRobot;
import org.opencv.core.Mat;
import org.opencv.core.Point;
import org.opencv.core.Scalar;
import org.opencv.imgproc.Imgproc;

/**
* This is a demo program showing the use of OpenCV to do vision processing. The
* image is acquired from the Axis camera, then a rectangle is put on the image and
* sent to the dashboard. OpenCV has many methods for different types of
* processing.
*/
public class Robot extends IterativeRobot {
Thread visionThread;

@Override
public void robotInit() {
visionThread = new Thread(() -> {
// Get the Axis camera from CameraServer
AxisCamera camera = CameraServer.getInstance().addAxisCamera("axis-camera.local");
// Set the resolution
camera.setResolution(640, 480);

// Get a CvSink. This will capture Mats from the camera
CvSink cvSink = CameraServer.getInstance().getVideo();
// Setup a CvSource. This will send images back to the Dashboard
CvSource outputStream = CameraServer.getInstance().putVideo("Rectangle", 640, 480);

// Mats are very memory expensive. Lets reuse this Mat.
Mat mat = new Mat();

// This cannot be 'true'. The program will never exit if it is. This
// lets the robot stop this thread when restarting robot code or
// deploying.
while (!Thread.interrupted()) {
// Tell the CvSink to grab a frame from the camera and put it
// in the source mat. If there is an error notify the output.
if (cvSink.grabFrame(mat) == 0) {
// Send the output the error.
outputStream.notifyError(cvSink.getError());
// skip the rest of the current iteration
continue;
}
// Put a rectangle on the image
Imgproc.rectangle(mat, new Point(100, 100), new Point(400, 400),
new Scalar(255, 255, 255), 5);
// Give the output stream a new image to display
outputStream.putFrame(mat);
}
});
visionThread.setDaemon(true);
visionThread.start();
}
}