Adnroid 使用安卓自带的人脸识别API

import android.app.Activity;
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.os.Bundle;
import android.util.Log;
import android.view.ViewGroup;
import android.widget.ImageView;

public class MainActivity extends Activity {

private final int MAX_FACES = 5;    //最大可识别的人脸数

private ImageView mIv;
private Bitmap mFaceBitmap;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);

//创建一个ImageView，加载到Activity视图上
mIv = new ImageView(this);
setContentView(mIv, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));
//要进行人脸识别的图片
mFaceBitmap = BitmapFactory.decodeResource(getResources(), R.mipmap.face);

mIv.setImageBitmap(mFaceBitmap);

//因为这是一个耗时的操作，所以放到另一个线程中运行
new Thread(new Runnable() {
@Override
public void run() {
FaceDetector.Face[] faces = new FaceDetector.Face[MAX_FACES];
//格式必须为RGB_565才可以识别
Bitmap bmp = mFaceBitmap.copy(Bitmap.Config.RGB_565, true);
//返回识别的人脸数
int faceCount = new FaceDetector(bmp.getWidth(), bmp.getHeight(), MAX_FACES).findFaces(bmp, faces);
bmp.recycle();
bmp = null;
Log.e("tag", "识别的人脸数:" + faceCount);

if (faceCount > 0) {
final Bitmap bitmap = parseBitmap(faces, faceCount);
//显示处理后的图片
mIv.post(new Runnable() {
@Override
public void run() {
mIv.setImageBitmap(bitmap);
}
});
}
}
}).start();
}

/**
* 在人脸上画矩形
*/
private Bitmap parseBitmap(FaceDetector.Face[] faces, int faceCount){
Bitmap bitmap = Bitmap.createBitmap(mFaceBitmap.getWidth(), mFaceBitmap.getHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap);
Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mPaint.setColor(Color.YELLOW);
mPaint.setStrokeWidth(10);
mPaint.setStyle(Paint.Style.STROKE);

canvas.drawBitmap(mFaceBitmap, 0, 0, mPaint);
for (int i = 0; i < faceCount; i++){
//双眼的中心点
PointF midPoint = new PointF();
faces[i].getMidPoint(midPoint);
//双眼的距离
float eyeDistance = faces[i].eyesDistance();
//画矩形
canvas.drawRect(midPoint.x - eyeDistance, midPoint.y - eyeDistance, midPoint.x + eyeDistance, midPoint.y + eyeDistance, mPaint);
}

return bitmap;
}
}