Java 级联分类器类使用示例

实例1: initClassifier

import org.opencv.objdetect.CascadeClassifier; //导入依赖的package包/类
private void initClassifier() {
    try {
        InputStream is = getResources()
                .openRawResource(R.raw.lbpcascade_frontalface);
        File cascadeDir = getDir("cascade", Context.MODE_PRIVATE);
        File cascadeFile = new File(cascadeDir, "lbpcascade_frontalface.xml");
        FileOutputStream os = new FileOutputStream(cascadeFile);
        byte[] buffer = new byte[4096];
        int bytesRead;
        while ((bytesRead = is.read(buffer)) != -1) {
            os.write(buffer, 0, bytesRead);
        }
        is.close();
        os.close();
        classifier = new CascadeClassifier(cascadeFile.getAbsolutePath());
    } catch (Exception e) {
        e.printStackTrace();
    }
}
 

实例2: loop

import org.opencv.objdetect.CascadeClassifier; //导入依赖的package包/类
public static void loop (CascadeClassifier classifier, Mat mat, ImgWindow window, VideoCapture video) {
	video.read(mat);
	System.out.println(mat);
	if (!mat.empty()) {
		MatOfRect rects = new MatOfRect();
		long start = System.nanoTime();
		classifier.detectMultiScale(mat, rects);
		System.out.println((System.nanoTime()-start)/1000000000.0);
		window.setImage(mat);
		Graphics2D g = window.begin();
		g.setColor(Color.RED);
		for(Rect r: rects.toArray()) {
			g.drawRect(r.x, r.y, r.width, r.height);
		}
		window.end();
	}
}
 

实例3: run

import org.opencv.objdetect.CascadeClassifier; //导入依赖的package包/类
public void run() {
  System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
  String base = "C:/Books in Progress/Java for Data Science/Chapter 10/OpenCVExamples/src/resources";
  CascadeClassifier faceDetector = 
          new CascadeClassifier(base + "/lbpcascade_frontalface.xml");
  
  Mat image = Imgcodecs.imread(base + "/images.jpg");

  MatOfRect faceVectors = new MatOfRect();
  faceDetector.detectMultiScale(image, faceVectors);

  out.println(faceVectors.toArray().length + " faces found");

  for (Rect rect : faceVectors.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));
  }
  Imgcodecs.imwrite("faceDetection.png", image);
}