准备 :

下载openCV安装包 : https://opencv.org/

安装包安装之后支持多种语言环境，此处使用Java，在Eclipse中引入 openCV目录下的java/opencv-320.jar，同时配置openCV库路径。

Eclipse配置openCV

代码实现 :

package test;import org.opencv.core.Core;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.objdetect.CascadeClassifier;import org.opencv.imgcodecs.Imgcodecs;import org.opencv.imgproc.Imgproc;public class Test {    //引入训练好的人脸识别XML文件static String PAHT = "E:/GOF/OpenCV/bin/test/haarcascade_frontalface_alt.xml";static String IMAGE_PATH = "E:/GOF/OpenCV/src/test/a.jpg";static String productPath = "E:/GOF/OpenCV";public static void main(String[] args) {System.loadLibrary(Core.NATIVE_LIBRARY_NAME);String Path = Test.class.getResource("haarcascade_frontalface_alt.xml").getPath();System.out.println(Path);CascadeClassifier faceDetector = new CascadeClassifier(PAHT);Mat image = Imgcodecs.imread(IMAGE_PATH);MatOfRect faceDetections = new MatOfRect();faceDetector.detectMultiScale(image, faceDetections);System.out.println(String.format("Detected %s faces", faceDetections.toArray().length));for (Rect rect : faceDetections.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));}String filename = "ouput.png";System.out.println(String.format("Writing %s", filename));boolean flag = Imgcodecs.imwrite(filename, image);}}

实现效果 :

对人脸区域写入边框