Android人脸检测类FaceDetector

 

根据文档描述，输入图片必须为Bitmap RGB565格式。

 

人脸的检测方法是用双眼来检测人脸的位置，也就是说无法检测到嘴、侧脸等，双眼必须同时可见，并且眼镜会影响检测的效果。

 

实际上，FaceDetector检测到的并不是人的全脸，而只是双眼。

 

实际测试中，发现图片太小的话检测不到人脸，试验中使用小于100x100的图片检测不到人脸，但是由于Android内存有限，图片太大的话，会出现无法加载图片的异常。

 

检测到的人脸存放到FaceDetector.Face类中，该类无法再扩展。从该类可以获取到人眼的中心位置和双眼之间的具体。

 

 

package name.feisky.face;

 

import android.app.Activity;

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;

import android.media.FaceDetector.Face;

import android.os.Bundle;

import android.view.View;

 

public class AndroidFaceDetector extends Activity {

    /** Called when the activity is first created. */

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(new myView(this));

    }

 

    private class myView extends View{

 

        private int imageWidth, imageHeight;

        private int numberOfFace = 5;

        private FaceDetector myFaceDetect;

        private FaceDetector.Face[] myFace;

        float myEyesDistance;

        int numberOfFaceDetected;

 

        Bitmap myBitmap;

 

        public myView(Context context) {

            super(context);

            BitmapFactory.Options BitmapFactoryOptionsbfo = new BitmapFactory.Options();

            BitmapFactoryOptionsbfo.inPreferredConfig = Bitmap.Config.RGB_565;

            myBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.pp, BitmapFactoryOptionsbfo);

            imageWidth = myBitmap.getWidth();

            imageHeight = myBitmap.getHeight();

            myFace = new FaceDetector.Face[numberOfFace];

            myFaceDetect = new FaceDetector(imageWidth, imageHeight, numberOfFace);

            numberOfFaceDetected = myFaceDetect.findFaces(myBitmap, myFace);

        }

 

        protected void onDraw(Canvas canvas) {

            // TODO Auto-generated method stub

 

            canvas.drawBitmap(myBitmap, 0, 0, null);

 

            Paint myPaint = new Paint();

            myPaint.setColor(Color.GREEN);

            myPaint.setStyle(Paint.Style.STROKE);

            myPaint.setStrokeWidth(3);

 

            for(int i=0; i < numberOfFaceDetected; i++)

            {

                Face face = myFace[i];

                PointF myMidPoint = new PointF();

                face.getMidPoint(myMidPoint);

                myEyesDistance = face.eyesDistance();

                canvas.drawRect(

                        (int)(myMidPoint.x - myEyesDistance),

                        (int)(myMidPoint.y - myEyesDistance),

                        (int)(myMidPoint.x + myEyesDistance),

                        (int)(myMidPoint.y + myEyesDistance),

                        myPaint);

            }

        }

    }

}

 

 

参考：http://www.anddev.org/quick_and_easy_facedetector_demo-t3856.html