JavaCV实现人脸检测功能

/*  * Copyright (C) 2010,2011,2012 Samuel Audet  *  * FacePreview - A fusion of OpenCV's facedetect and Android's CameraPreview samples,  *        with JavaCV + JavaCPP as the glue in between.  *  * This file was based on CameraPreview.java that came with the Samples for  * Android SDK API 8, revision 1 and contained the following copyright notice:  *  * Copyright (C) 2007 The Android Open Source Project  *  * Licensed under the Apache License, Version 2.0 (the "License");  * you may not use this file except in compliance with the License.  * You may obtain a copy of the License at  *  *   http://www.apache.org/licenses/LICENSE-2.0  *  * Unless required by applicable law or agreed to in writing, software  * distributed under the License is distributed on an "AS IS" BASIS,  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  * See the License for the specific language governing permissions and  * limitations under the License.  *  *  * IMPORTANT - Make sure the AndroidManifest.xml file looks like this:  *  * <?xml version="1.0" encoding="utf-8"?>  * <manifest xmlns:android="http://schemas.android.com/apk/res/android"  *   package="com.googlecode.javacv.facepreview"  *   android:versionCode="1"  *   android:versionName="1.0" >  *   <uses-sdk android:minSdkVersion="4" />  *   <uses-permission android:name="android.permission.CAMERA" />  *   <uses-feature android:name="android.hardware.camera" />  *   <application android:label="@string/app_name">  *     <activity  *       android:name="FacePreview"  *       android:label="@string/app_name"  *       android:screenOrientation="landscape">  *       <intent-filter>  *         <action android:name="android.intent.action.MAIN" />  *         <category android:name="android.intent.category.LAUNCHER" />  *       </intent-filter>  *     </activity>  *   </application>  * </manifest>  */  package com.googlecode.javacv.facepreview;  import android.app.Activity; import android.app.AlertDialog; import android.content.Context; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.ImageFormat; import android.graphics.Paint; import android.hardware.Camera; import android.hardware.Camera.Size; import android.os.Bundle; import android.view.SurfaceHolder; import android.view.SurfaceView; import android.view.View; import android.view.Window; import android.view.WindowManager; import android.widget.FrameLayout; import java.io.File; import java.io.IOException; import java.nio.ByteBuffer; import java.util.List; import com.googlecode.javacpp.Loader; import com.googlecode.javacv.cpp.opencv_objdetect;  import static com.googlecode.javacv.cpp.opencv_core.*; import static com.googlecode.javacv.cpp.opencv_imgproc.*; import static com.googlecode.javacv.cpp.opencv_objdetect.*; import static com.googlecode.javacv.cpp.opencv_highgui.*;  // ----------------------------------------------------------------------  public class FacePreview extends Activity {   private FrameLayout layout;   private FaceView faceView;   private Preview mPreview;    @Override   protected void onCreate(Bundle savedInstanceState) {     // Hide the window title.     requestWindowFeature(Window.FEATURE_NO_TITLE);      super.onCreate(savedInstanceState);      getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);      // Create our Preview view and set it as the content of our activity.     try {       layout = new FrameLayout(this);       faceView = new FaceView(this);       mPreview = new Preview(this, faceView);       layout.addView(mPreview);       layout.addView(faceView);       setContentView(layout);     } catch (IOException e) {       e.printStackTrace();       new AlertDialog.Builder(this).setMessage(e.getMessage()).create().show();     }   } }  // ----------------------------------------------------------------------  class FaceView extends View implements Camera.PreviewCallback {   public static final int SUBSAMPLING_FACTOR = 4;    private IplImage grayImage;   private CvHaarClassifierCascade classifier;   private CvMemStorage storage;   private CvSeq faces;    public FaceView(FacePreview context) throws IOException {     super(context);      // Load the classifier file from Java resources.     File classifierFile = Loader.extractResource(getClass(),       "/com/googlecode/javacv/facepreview/haarcascade_frontalface_alt2.xml",       context.getCacheDir(), "classifier", ".xml");     if (classifierFile == null || classifierFile.length() <= 0) {       throw new IOException("Could not extract the classifier file from Java resource.");     }      // Preload the opencv_objdetect module to work around a known bug.     Loader.load(opencv_objdetect.class);     classifier = new CvHaarClassifierCascade(cvLoad(classifierFile.getAbsolutePath()));     classifierFile.delete();     if (classifier.isNull()) {       throw new IOException("Could not load the classifier file.");     }     storage = CvMemStorage.create();   }    public void onPreviewFrame(final byte[] data, final Camera camera) {     try {       Camera.Size size = camera.getParameters().getPreviewSize();       processImage(data, size.width, size.height);       camera.addCallbackBuffer(data);     } catch (RuntimeException e) {       // The camera has probably just been released, ignore.     }   }    protected void processImage(byte[] data, int width, int height) {     // First, downsample our image and convert it into a grayscale IplImage     int f = SUBSAMPLING_FACTOR;     if (grayImage == null || grayImage.width() != width/f || grayImage.height() != height/f) {       grayImage = IplImage.create(width/f, height/f, IPL_DEPTH_8U, 1);     }     int imageWidth = grayImage.width();     int imageHeight = grayImage.height();     int dataStride = f*width;     int imageStride = grayImage.widthStep();     ByteBuffer imageBuffer = grayImage.getByteBuffer();     for (int y = 0; y < imageHeight; y++) {       int dataLine = y*dataStride;       int imageLine = y*imageStride;       for (int x = 0; x < imageWidth; x++) {         imageBuffer.put(imageLine + x, data[dataLine + f*x]);       }     }     IplImage grayImageT = IplImage.create(height/f, width/f, IPL_DEPTH_8U, 1);     //cvSaveImage("/storage/emulated/0/Pictures/grayImage.jpg",grayImage);     cvTranspose(grayImage,grayImageT);     //cvSaveImage("/storage/emulated/0/Pictures/grayImageT.jpg",grayImageT);     cvFlip(grayImageT,grayImageT,0);     //cvSaveImage("/storage/emulated/0/Pictures/grayImageT_X.jpg",grayImageT);     cvFlip(grayImageT,grayImageT,1);     //cvSaveImage("/storage/emulated/0/Pictures/grayImageT_Y.jpg",grayImageT);      cvClearMemStorage(storage);     faces = cvHaarDetectObjects(grayImageT, classifier, storage, 1.1, 3, CV_HAAR_DO_CANNY_PRUNING);     postInvalidate();   }    @Override   protected void onDraw(Canvas canvas) {     Paint paint = new Paint();     paint.setColor(Color.RED);     paint.setTextSize(20);      String s = "FacePreview - This side up.";     float textWidth = paint.measureText(s);     canvas.drawText(s, (getWidth()-textWidth)/2, 20, paint);      if (faces != null) {       paint.setStrokeWidth(2);       paint.setStyle(Paint.Style.STROKE);       float scaleX = (float)getWidth()/grayImage.width();       float scaleY = (float)getHeight()/grayImage.height();       int total = faces.total();       for (int i = 0; i < total; i++) {         CvRect r = new CvRect(cvGetSeqElem(faces, i));         int x = r.x(), y = r.y(), w = r.width(), h = r.height();         canvas.drawRect(x*scaleX, y*scaleY, (x+w)*scaleX, (y+h)*scaleY, paint);       }     }     else{       canvas.drawText("meiyoujiancedao", (getWidth()-textWidth)/2, 20, paint);     }   } }  // ----------------------------------------------------------------------  class Preview extends SurfaceView implements SurfaceHolder.Callback {   SurfaceHolder mHolder;   Camera mCamera;   Camera.PreviewCallback previewCallback;    Preview(Context context, Camera.PreviewCallback previewCallback) {     super(context);     this.previewCallback = previewCallback;      // Install a SurfaceHolder.Callback so we get notified when the     // underlying surface is created and destroyed.     mHolder = getHolder();     mHolder.addCallback(this);     mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);   }    public void surfaceCreated(SurfaceHolder holder) {     // The Surface has been created, acquire the camera and tell it where     // to draw.     mCamera = Camera.open(Camera.CameraInfo.CAMERA_FACING_FRONT);     try {       mCamera.setPreviewDisplay(holder);     } catch (IOException exception) {       mCamera.release();       mCamera = null;       // TODO: add more exception handling logic here     }   }    public void surfaceDestroyed(SurfaceHolder holder) {     // Surface will be destroyed when we return, so stop the preview.     // Because the CameraDevice object is not a shared resource, it's very     // important to release it when the activity is paused.     mCamera.stopPreview();     mCamera.release();     mCamera = null;   }     private Size getOptimalPreviewSize(List<Size> sizes, int w, int h) {     final double ASPECT_TOLERANCE = 0.05;     double targetRatio = (double) w / h;     if (sizes == null) return null;      Size optimalSize = null;     double minDiff = Double.MAX_VALUE;      int targetHeight = h;      // Try to find an size match aspect ratio and size     for (Size size : sizes) {       double ratio = (double) size.width / size.height;       if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE) continue;       if (Math.abs(size.height - targetHeight) < minDiff) {         optimalSize = size;         minDiff = Math.abs(size.height - targetHeight);       }     }      // Cannot find the one match the aspect ratio, ignore the requirement     if (optimalSize == null) {       minDiff = Double.MAX_VALUE;       for (Size size : sizes) {         if (Math.abs(size.height - targetHeight) < minDiff) {           optimalSize = size;           minDiff = Math.abs(size.height - targetHeight);         }       }     }     return optimalSize;   }    public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {     // Now that the size is known, set up the camera parameters and begin     // the preview.     Camera.Parameters parameters = mCamera.getParameters();      List<Size> sizes = parameters.getSupportedPreviewSizes();     Size optimalSize = getOptimalPreviewSize(sizes, w, h);     parameters.setPreviewSize(optimalSize.width, optimalSize.height);      mCamera.setParameters(parameters);     if (previewCallback != null) {       mCamera.setPreviewCallbackWithBuffer(previewCallback);       Camera.Size size = parameters.getPreviewSize();       byte[] data = new byte[size.width*size.height*           ImageFormat.getBitsPerPixel(parameters.getPreviewFormat())/8];       mCamera.addCallbackBuffer(data);     }     mCamera.startPreview();   }  }