Android多媒体-人脸识别

package com.example.mydetect2;

import android.os.Bundle;
import android.app.Activity;
import android.util.Log;
import android.view.Menu;
import android.content.Context; 
import android.graphics.Bitmap; 
import android.graphics.BitmapFactory; 
import android.graphics.Canvas; 
import android.graphics.Color; 
import android.graphics.Paint; 
import android.graphics.PointF; 
import android.media.FaceDetector; 	//人脸识别的关键类
import android.media.FaceDetector.Face; 
import android.view.View; 

public class MainActivity2 extends Activity {

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		//setContentView(R.layout.activity_main_activity2);
		setContentView(new myView(this));	//使用自建的view来显示
		Log.i("zhangcheng","MainActivity2 run here");
	}

	private class myView extends View{
		private int imageWidth, imageHeight;
		private int numberOfFace = 5;		//最大检測的人脸数
		private FaceDetector myFaceDetect;	//人脸识别类的实例
		private FaceDetector.Face[] myFace;	//存储多张人脸的数组变量
		float myEyesDistance; 			//两眼之间的距离
		int numberOfFaceDetected; 		//实际检測到的人脸数
		Bitmap myBitmap;

		public myView(Context context){		//view类的构造函数，必须有
			super(context); 
			BitmapFactory.Options BitmapFactoryOptionsbfo = new BitmapFactory.Options(); 
			BitmapFactoryOptionsbfo.inPreferredConfig = Bitmap.Config.RGB_565;	//构造位图生成的參数，必须为565。类名+enum
			myBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.baby, BitmapFactoryOptionsbfo);	 
			imageWidth = myBitmap.getWidth(); 
			imageHeight = myBitmap.getHeight(); 
			myFace = new FaceDetector.Face[numberOfFace]; 		//分配人脸数组空间
			myFaceDetect = new FaceDetector(imageWidth, imageHeight, numberOfFace); 
			numberOfFaceDetected = myFaceDetect.findFaces(myBitmap, myFace); 	//FaceDetector 构造实例并解析人脸
			Log.i("zhangcheng","numberOfFaceDetected is " + numberOfFaceDetected);
		}
		
		protected void onDraw(Canvas canvas){			//override函数，必有
			canvas.drawBitmap(myBitmap, 0, 0, null);	//画出位图 
			Paint myPaint = new Paint(); 
			myPaint.setColor(Color.GREEN); 
			myPaint.setStyle(Paint.Style.STROKE); 
			myPaint.setStrokeWidth(3); 			//设置位图上paint操作的參数

			for(int i=0; i < numberOfFaceDetected; i++){
				Face face = myFace[i];
				PointF myMidPoint = new PointF(); 
				face.getMidPoint(myMidPoint); 
				myEyesDistance = face.eyesDistance(); 	//得到人脸中心点和眼间距离參数，并对每一个人脸进行画框
				canvas.drawRect( 			//矩形框的位置參数
                        (int)(myMidPoint.x - myEyesDistance), 
                        (int)(myMidPoint.y - myEyesDistance), 
                        (int)(myMidPoint.x + myEyesDistance), 
                        (int)(myMidPoint.y + myEyesDistance), 
                        myPaint);
			}
		}
	}
}