Detect your face using opencv in java

     // first SetUp Your OpenCV lib with Eclips IDE

  
package opencvtest;

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.highgui.Highgui;
import org.opencv.objdetect.CascadeClassifier;

//
// Detects faces in an image, draws boxes around them, and writes the results
// to "faceDetection.png".
//
class DetectFaceDemo {
  public void run() {
    System.out.println("\nRunning DetectFaceDemo");

    // Create a face detector from the cascade file in the resources
    // directory.
   // CascadeClassifier faceDetector = new CascadeClassifier(getClass().getResource("lbpcascade_frontalface.xml").getPath());
   CascadeClassifier faceDetector = new CascadeClassifier("D:/javaTech/OpenCV/opencv/sources/data/lbpcascades/lbpcascade_frontalface.xml");
//    Mat image = Highgui.imread("C:/Users/kiit1/Desktop/IMG_2096.JPG");
    Mat image = Highgui.imread("C:/Users/kiit1/Desktop/b.JPG");

    // Detect faces in the image.
    // MatOfRect is a special container class for Rect.
    MatOfRect faceDetections = new MatOfRect();
    faceDetector.detectMultiScale(image, faceDetections);

    System.out.println(String.format("Detected %s faces", faceDetections.toArray().length));

    // Draw a bounding box around each face.
    for (Rect rect : faceDetections.toArray()) {
        Core.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.
    String filename = "C:/Users/kiit1/Desktop/lenafaceDetection.png";
    System.out.println(String.format("Writing %s", filename));
    Highgui.imwrite(filename, image);
  }
}

//Main.java (Execute this)
package opencvtest;
import java.awt.image.BufferedImage;
import java.awt.image.DataBufferByte;

import java.io.File;
import javax.imageio.ImageIO;

import org.opencv.core.Core;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.imgproc.Imgproc;

public class Main {
   public static void main( String[] args ) { 
   
      try {
         System.loadLibrary( Core.NATIVE_LIBRARY_NAME );
         File input = new File("C:/Users/kiit1/Desktop/lena.png");
         BufferedImage image = ImageIO.read(input); 

         byte[] data = ((DataBufferByte) image.getRaster().getDataBuffer()).getData();
         Mat mat = new Mat(image.getHeight(), image.getWidth(), CvType.CV_8UC3);
         mat.put(0, 0, data);

         Mat mat1 = new Mat(image.getHeight(),image.getWidth(),CvType.CV_8UC1);
         Imgproc.cvtColor(mat, mat1, Imgproc.COLOR_RGB2GRAY);

         byte[] data1 = new byte[mat1.rows() * mat1.cols() * (int)(mat1.elemSize())];
         mat1.get(0, 0, data1);
         BufferedImage image1 = new BufferedImage(mat1.cols(),mat1.rows(), BufferedImage.TYPE_BYTE_GRAY);
         image1.getRaster().setDataElements(0, 0, mat1.cols(), mat1.rows(), data1);

         File ouptut = new File("C:/Users/kiit1/Desktop/grayscale.jpg");
         ImageIO.write(image1, "jpg", ouptut);
         
      } catch (Exception e) {
         System.out.println("Error: " + e.getMessage());
      }
   }
}
 

OutPut