opencv Using Cascade Classifiers In Java Detecting images from a video device
Example
This example introduces the VideoCapture class, where we use it to take an image from a webcam and save it to an image.
import org.opencv.core.Mat;
import org.opencv.core.MatOfRect;
import org.opencv.core.Point;
import org.opencv.core.Rect;
import org.opencv.core.Scalar;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.imgproc.Imgproc;
import org.opencv.objdetect.CascadeClassifier;
import org.opencv.videoio.VideoCapture;
public class Classifier {
private CascadeClassifier diceCascade = new
CascadeClassifier("res/newMethod/diceCascade.xml");
private Mat image;
private String loc = "path/to/image.png";
private String output = "path/to/output.png";
private VideoCapture vc = new VideoCapture();
public void detImg() {
vc.open(0); // Opens the video stream
Mat image = new Mat(); // Creates an empty matrix
vc.read(image); // Reads the image from the video stream and
writes it to the image matrix.
MatOfRect diceDetections = new MatOfRect(); // Output container
diceCascade.detectMultiScale(image, diceDetections); // Performs the detection
// Draw a bounding box around each detection.
for (Rect rect : diceDetections.toArray()) {
Imgproc.rectangle(image, new Point(rect.x, rect.y),
new Point(rect.x + rect.width, rect.y + rect.height),
new Scalar(0, 255, 0));
}
// Save the visualized detection.
Imgcodecs.imwrite(output, image);
vc.release(); // Closes the stream.
}
}
