android人脸识别.doc

在Android实现人脸识别的详细过程发布者：aime达娃他的主页关注的信息收藏的信息推荐的信息参加的群组时间：2012-12-03 00:52:09-照相时，在预览画面上提示用户人脸的位置，并完成自动对焦等，是个错的应用; 下面是实现细节我们知道在android的代码中已有人脸识别的底层算法代码，而且在framework层也封了调用的API函数1. extern/neven 目录下是实现人脸识别的算法代码。2. 添加获取照相时预览图片数据，可以在onPreviewFrame回调函数中得。在开始预览的地方，用mCameraDevice.setPreviewCallback(mPreviewCallback);设置预览回调函数。3.import android.media.FaceDetector;import android.media.FaceDetector.Face;/Harrison add private void DrawRectOnFace() if (numberOfFaceDetected != 0) Face mFace1 = mFace0;PointF midPoint = new PointF(); mFace1.getMidPoint(midPoint);if (Math.abs(mPreMidPoint.x-midPoint.x) 50) & (Math.abs(mPreMidPoint.y-midPoint.y) 50) Log.i(Harrison, not draw Rect .);return ;mPreMidPoint.x = midPoint.x;mPreMidPoint.y = midPoint.y;mFindFaceView.setVisibility(View.VISIBLE); else mPreMidPoint.x = 0;mPreMidPoint.y = 0;mFindFaceView.clearDraw();mFindFaceView.setVisibility(View.GONE);return;mFindFaceView.drawRects(mFace, numberOfFaceDetected);/调用API找人脸，需要import进软件包哦！private void FindFacesInBitmap(Bitmap myBitmap) imageWidth = myBitmap.getWidth();imageHeight = myBitmap.getHeight();Log.i(Harrison, imageWidth=+imageWidth+, imageHeight=+imageHeight);mFace = new FaceDetector.FacenumberOfFace;mFaceDetect = new FaceDetector(imageWidth, imageHeight, numberOfFace);numberOfFaceDetected = mFaceDetect.findFaces(myBitmap, mFace);Log.i(Harrison, numberOfFaceDetected=+numberOfFaceDetected);private Bitmap rotateMyBitmap(Bitmap bitmap) int width = bitmap.getWidth(); int height = bitmap.getHeight(); Matrix matrix = new Matrix(); matrix.postRotate(90); /椤烘椂閽熸棆杞?0搴?Bitmap rotateBitmap = Bitmap.createBitmap(bitmap, 0, 0, width, height, matrix, true);return rotateBitmap;private Bitmap scaleMyBitmap(Bitmap bitmap) int width = bitmap.getWidth(); int height = bitmap.getHeight(); int nWidth = mFindFaceView.getFaceViewWidth(); int nHeight = mFindFaceView.getFaceViewHeight(); / Log.i(Harrison, nWidth=+nWidth+, nHeight+nHeight);float scaleWidth = (float) nWidth)/width; float scaleHeight = (float)nHeight)/height; Matrix matrix = new Matrix(); matrix.postScale(scaleWidth, scaleHeight); Bitmap resizedBitmap = Bitmap.createBitmap(bitmap, 0, 0, width, height, matrix, true);return resizedBitmap;/处理图片格式，一般摄像头抓到的数据为ImageFormat.NV21，不同的格式，需要调整的。private void decodeToBitMap(byte data, android.hardware.Camera _camera) mCameraDevice.setPreviewCallback(null);Size size = mCameraDevice.getParameters().getPreviewSize();/FileOutputStream outStream = null;try YuvImage image = new YuvImage(data, ImageFormat.NV21, size.width, size.height, null);if (image != null) ByteArrayOutputStream stream = new ByteArrayOutputStream();pressToJpeg(new Rect(0, 0, size.width, size.height), 80, stream);/ outStream = new FileOutputStream(String.format(/sdcard/%d.jpg, System.currentTimeMillis();/ outStream.write(stream.toByteArray();/ outStream.close();/ Log.i(Harrison, write file to sdcard.);/在我的手机上有两种预览模式，发现全屏模式时需要调整图片的大小才能正确定位。Bitmap myBitmap=BitmapFactory.decodeByteArray(stream.toByteArray(), 0, stream.size();stream.close();if (mPreviewLayoutProxy.getFullScreenMode() / fullscreen mode Bitmap tmpScaleBmp=null;Bitmap tmpRotateBmp=null;/手机是竖屏横排是与其别的哦if (mOrientation/90) = 0) | (mOrientation/90) = 2) tmpRotateBmp = rotateMyBitmap(myBitmap);tmpScaleBmp = scaleMyBitmap(tmpRotateBmp);FindFacesInBitmap(tmpScaleBmp);if (tmpRotateBmp != null) tmpRotateBmp.recycle();tmpRotateBmp = null; else FindFacesInBitmap(scaleMyBitmap(myBitmap);if (tmpScaleBmp != null) tmpScaleBmp.recycle();tmpScaleBmp = null; else /normal modeFindFacesInBitmap(myBitmap);DrawRectOnFace();if (myBitmap != null) myBitmap.recycle();myBitmap = null; catch (Exception ex) Log.e(Sys, Error: + ex.getMessage(); mCameraDevice.setPreviewCallback(mPreviewCallback);private final class PostPreviewCallback implements PreviewCallback Overridepublic void onPreviewFrame(byte data, android.hardware.Camera camera) decodeToBitMap(data, camera);我们知道，相机预览是用 SurfaceView来显示图片的；在我们画提示框时，不能直接用那个view的，会出现黑屏的状态，预览的画面也不流畅的。添加一个一样大小的SurfaceView来提示。在xml布局中添加我的画提示框代码：package com.android.camera;import android.content.Context;import android.graphics.Canvas;import android.graphics.Bitmap;import android.graphics.Color;import android.graphics.Paint;import android.graphics.Rect; import android.graphics.Paint.Style;import android.graphics.PixelFormat;import android.graphics.PorterDuffXfermode;import android.graphics.PorterDuff;import android.util.AttributeSet;import android.util.Log;import android.view.SurfaceHolder;import android.view.SurfaceView;import android.view.View;import android.graphics.PointF;import android.media.FaceDetector;import android.media.FaceDetector.Face;public class FindFaceView extends SurfaceView implements SurfaceHolder.Callbackprotected SurfaceHolder sh;private SurfaceHolder mCameraSh;private int mWidth;private int mHeight;private float mEyesDistance;public FindFaceView(Context context, AttributeSet attrs) super(context, attrs);/ TODO Auto-generated constructor stubsh = getHolder();sh.addCallback(this);sh.setFormat(PixelFormat.TRANSPARENT);setZOrderOnTop(true);public void surfaceChanged(SurfaceHolder arg0, int arg1, int w, int h) / TODO Auto-generated method stubmWidth = w;mHeight = h;public void surfaceCreated(SurfaceHolder arg0) / TODO Auto-generated method stubpublic void surfaceDestroyed(SurfaceHolder arg0) / TODO Auto-generated method stubvoid setCameraPreviewSurfaceHolder(SurfaceHolder sh) mCameraSh = sh;public int getFaceViewWidth() return mWidth;public int getFaceViewHeight() return mHeight;void clearDraw() Canvas canvas = sh.lockCanvas();Paint clipPaint = new Paint();clipPaint.setAntiAlias(true);clipPaint.setStyle(Paint.Style.STROKE);clipPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR);canvas.drawPaint(clipPaint);sh.unlockCanvasAndPost(canvas);public void drawRects(FaceDetector.Face mFace, int numberOfFaceDetected) Canvas canvas = sh.lockCanvas();Paint clipPaint = new Paint();clipPaint.setAntiAlias(true);clipPaint.setStyle(Paint.Style.STROKE);clipPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR);canvas.drawPaint(clipPaint);canvas.drawColor(Color.TRANSPARENT);Paint p = new Paint();p.setAntiAlias(true);p.setColor(Color.RED);p.setStyle(Style.STROKE);for (int i = 0; i numberOfFaceDetected; i+) / if (0 = i) / p.setColor(Color.WHITE);/ else / p.setColor(Color.GRAY);/ Face face = mFacei;PointF myMidPoint = new PointF();face.getMidPoint(myMidPoint);mEyesDistance = face.eyesDistance();Log.i(Harrison, i=+i+(+myMidPoint.x+, +myMidPoint.y+);canvas.drawRect(int)(myMidPoint.x-mEyesDistance),(int)(myMidPoint.y-mEyesDistance),(int)(myMidPoint.x+mEyesDistance),(int)(myMidPoint.y+mEyesDistance), p);sh.unlockCanvasAndPost(canvas);/测试两个View是否错移public void dr