<dependency>

    <groupId>org.bytedeco</groupId>

    <artifactId>javacv-platform</artifactId>

    <version>1.4.2</version>

</dependency>

<dependency>

    <groupId>org.bytedeco.javacpp-presets</groupId>

    <artifactId>opencv-platform</artifactId>

    <version>3.4.2-1.4.2</version>

</dependency>

import static org.bytedeco.javacpp.opencv_imgproc.COLOR_BGRA2GRAY;

import static org.bytedeco.javacpp.opencv_imgproc.cvtColor;

import static org.bytedeco.javacpp.opencv_imgproc.rectangle;

import static org.bytedeco.javacpp.opencv_imgproc.resize;

import javax.swing.JFrame;

import org.bytedeco.javacpp.opencv_core.Mat;

import org.bytedeco.javacpp.opencv_core.Rect;

import org.bytedeco.javacpp.opencv_core.RectVector;

import org.bytedeco.javacpp.opencv_core.Scalar;

import org.bytedeco.javacpp.opencv_core.Size;

import org.bytedeco.javacpp.opencv_imgcodecs;

import org.bytedeco.javacpp.opencv_objdetect.CascadeClassifier;

import org.bytedeco.javacv.CanvasFrame;

import org.bytedeco.javacv.Frame;

import org.bytedeco.javacv.FrameGrabber.Exception;

import org.bytedeco.javacv.OpenCVFrameConverter;

import org.bytedeco.javacv.OpenCVFrameGrabber;

/**

 * 调用本地摄像头窗口视频

 *

 * @author eguid

 * @version 2016年6月13日

 * @see javavcCameraTest

 * @since javacv1.2

 */

public class FaceDetect {

  public static void main(String[] args) throws Exception, InterruptedException {

    // 里面的整数值代表第N个摄像头，电脑内置默认为0，外置的从1开始

    OpenCVFrameConverter.ToMat converterToMat = new OpenCVFrameConverter.ToMat();

    OpenCVFrameGrabber grabber = new OpenCVFrameGrabber(0);

    grabber.start(); // 开始获取摄像头数据

    CanvasFrame canvas = new CanvasFrame("摄像头");// 新建一个窗口

    canvas.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    canvas.setAlwaysOnTop(true);

    Frame videoFrame = null;

    Mat videoMat = null;

    while (true) {

      if (!canvas.isDisplayable()) {// 窗口是否关闭

        grabber.stop();// 停止抓取

        grabber.close();

        System.exit(2);// 退出

      }

      // 获取摄像头图像并放到窗口上显示， 这里的Frame是一帧视频图像

      videoFrame = grabber.grab();

      videoMat = converterToMat.convert(videoFrame);

      Mat videoMatGray = new Mat();

      // 图片灰度处理，更容易识别出人脸

      cvtColor(videoMat, videoMatGray, COLOR_BGRA2GRAY);

      Mat detectFace = detectFace(videoMat);

      videoFrame = converterToMat.convert(detectFace);

      canvas.showImage(videoFrame);// 显示带方框的人脸

      Thread.sleep(50);// 50毫秒刷新一次图像

    }

  }

  /**

   * 人脸检测

   *

   * @param videoMat

   * @return

   * @throws Exception

   */

  public static Mat detectFace(Mat videoMat) throws Exception {

    System.out.println("Running DetectFace ... ");

    // 从配置文件lbpcascade_frontalface.xml中创建一个人脸识别器，该文件位于opencv安装目录中

    CascadeClassifier faceDetector = new CascadeClassifier(

        "D:\\app\\opencv3.4.2\\sources\\data\\haarcascades\\haarcascade_frontalface_alt.xml");

    // 在图片中检测人脸

    RectVector faces = new RectVector();

    faceDetector.detectMultiScale(videoMat, faces);

    System.out.println(String.format("Detected %s faces", faces.size()));

    Rect[] rects = faces.get();

    if (rects != null && rects.length >= 1) {

      for (Rect rect : rects) {

        rectangle(videoMat, rect, Scalar.RED);

        saveFace(videoMat, rect);

      }

    }

    faceDetector.close();

    return videoMat;

  }

  /**

   * 抓取人脸保存为图片

   *

   * @param image

   * @param rect

   */

  private static void saveFace(Mat image, Rect rect) {

    Mat sub = image.rowRange(rect.y(), rect.y() + rect.height()).colRange(rect.x(), rect.x() + rect.width());

    Mat mat = new Mat();

    Size size = new Size(100, 100);

    resize(sub, mat, size);

    opencv_imgcodecs.imwrite("d:\\test\\capture\\" + System.currentTimeMillis() + ".png", mat);

  }

}