java人脸识别在项目中的应用(一)

      本例程是识别图片中的人脸，并画出识别出的人脸的位置。在网上找了很久，用java实现人脸识别技术很难找到。多是依靠JNI 调用OpenCV本地方法实现的。那么这里先来说说这种方法：

        先认识一下JNI 和OpenCV

        JNI是Java Native Interface的缩写，中文为JAVA本地调用。从Java 1.1开始，Java Native Interface (JNI)标准成为java平台的一部分，它允许Java代码和其他语言写的代码进行交互。

      OpenCV是Intel公司支持的开源计算机视觉库。它轻量级而且高效——由一系列 C 函数和少量 C++ 类构成，实现了图像处理和计算机视觉方面的很多通用算法。 

     将源代码中的dll文件(cv097.dll,cxcore097.dll,highgui097.dll,JNI2OpenCV.dll)放入C:\WINDOWS\system32目录下。

     现在开始上源码：

public class JNIOpenCV{ 
	public JNIOpenCV() {}
  static{ 
            System.out.println("开始加载JNI2OpenCV.dll");
            System.loadLibrary("JNI2OpenCV");
            System.out.println("加载完成");
  }  
   // 加载动态链接库
  public native int[] detectFace(int minFaceWidth, int minFaceHeight, String cascade, String filename);  
   // 声明本地方法    
}

 

public class FaceDetection {
	private JNIOpenCV myJNIOpenCV;
	public FaceDetection(String intputFileName,String outputFileName) {
		myJNIOpenCV = new JNIOpenCV();
		String filename = intputFileName;
		String outputFilename = outputFileName;
		String cascade = "F:\\detectface\\xml\\haarcascade_frontalface_alt2.xml";
		int[] detectedFaces = myJNIOpenCV.detectFace(40, 40, cascade, filename);
		int numFaces = detectedFaces.length / 4;
		if(numFaces > 0){
			System.out.println("有脸！有 "+ numFaces + " 张脸");
		}else{
			System.out.println("没有脸！");
		}
    	for (int i = 0; i < numFaces; i++) {
    		System.out.println("Face " + i + ": " + detectedFaces[4 * i + 0] + " " + detectedFaces[4 * i + 1] + " " + detectedFaces[4 * i + 2] + " " + detectedFaces[4 * i + 3]);
    	}
    	int[][] RectInt=new int[numFaces][4];
		for (int i = 0; i < numFaces; i++) 
		{      
		   RectInt[i][0]=detectedFaces[4 * i + 0];
		   RectInt[i][1]=detectedFaces[4 * i + 1];
		   RectInt[i][2]=detectedFaces[4 * i + 2];
		   RectInt[i][3]=detectedFaces[4 * i + 3];
		}
		    if(new DrawInImg(filename,outputFilename,RectInt).DrawRect())
					System.out.println("File create success ! ");
			else
					System.out.println("File create error ! ");
		}
    
    public static void main(String args[]) {
       FaceDetection myFaceDetection = new FaceDetection("F:\\detectface\\image\\tt.jpg","F:\\detectface\\image\\tt2.jpg");
    }   
}

 

import java.awt.Color;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import javax.imageio.ImageIO;

public class DrawInImg {

	private boolean isDone = false;
	private String inputFileName = "";
	private String outputFileName = "";
	private int[][] RectInt;

	public DrawInImg(String inputFileName, String outputFileName,
			int[][] RectInt) {
		this.inputFileName = inputFileName;
		this.outputFileName = outputFileName;
		this.RectInt = RectInt;
	}

	public boolean DrawRect() {
		try {
			FileInputStream fis = new FileInputStream(inputFileName);
			FileOutputStream fos = new FileOutputStream(outputFileName);
			BufferedImage img = ImageIO.read(fis);
			Graphics g = img.getGraphics();
			g.setColor(Color.GREEN);
			for (int i = 0; i < RectInt.length; i++) {
				for (int j = 0; j < RectInt[i].length; j++) {
					g.drawRect(RectInt[i][0], RectInt[i][1], RectInt[i][2],
							RectInt[i][3]);
					// System.out.print(RectInt[i][j]+" ");
				}
				System.out.print("\r\n");
			}

			img.flush();
			g.dispose();
			ImageIO.write(img, "JPG", fos);

			while (true) {
				if (new File(outputFileName).exists()) {
					this.isDone = true;
					break;
				}
			}

		} catch (IOException ioe) {
			ioe = null;
		}

		return this.isDone;
	}

}

 注意：以上代码不能放在包下面，否则会运行不成功的。(原因是dll编译的时候没有带上包，如需包还需重新编译dll)。