Android调用OpenCV2.4.10实现二维码区域定位-创新互联

Android上使调用OpenCV 2.4.10 实现二维码区域定位（Z-xing 码），该文章主要用于笔者自己学习中的总结，暂贴出代码部分，待以后有时间再补充算法的详细细节。

Activity class Java 文件

package cn.hjq.android_capture; 
 
import java.io.BufferedWriter; 
import java.io.File; 
import java.io.FileOutputStream; 
import java.io.IOException; 
import java.io.OutputStreamWriter; 
import java.util.ArrayList; 
import java.util.List; 
 
import org.opencv.android.BaseLoaderCallback; 
import org.opencv.android.LoaderCallbackInterface; 
import org.opencv.android.OpenCVLoader; 
import org.opencv.core.*; 
import org.opencv.highgui.*; 
import org.opencv.imgproc.*; 
import org.opencv.utils.Converters; 
 
import android.graphics.Bitmap; 
import android.graphics.BitmapFactory; 
import android.graphics.Matrix; 
import android.hardware.Camera; 
import android.hardware.Camera.AutoFocusCallback; 
import android.hardware.Camera.Parameters; 
import android.hardware.Camera.PictureCallback; 
import android.os.Bundle; 
import android.os.Environment; 
import android.os.Handler; 
import android.app.Activity; 
import android.content.pm.ActivityInfo; 
import android.view.MotionEvent; 
import android.view.SurfaceHolder; 
import android.view.SurfaceHolder.Callback; 
import android.view.SurfaceView; 
import android.view.View; 
 
public class capture extends Activity { 
 private SurfaceView picSV; 
 private Camera camera; 
 private String strPicPath; 
  
 //OpenCV类库加载并初始化成功后的回调函数，在此我们不进行任何操作 
 private BaseLoaderCallback mLoaderCallback = new BaseLoaderCallback(this) { 
  @Override 
  public void onManagerConnected(int status) { 
   switch (status) { 
    case LoaderCallbackInterface.SUCCESS:{ 
    } break; 
    default:{ 
     super.onManagerConnected(status); 
    } break; 
   } 
  } 
 }; 
  
 @SuppressWarnings("deprecation") 
 @Override 
 protected void onCreate(Bundle savedInstanceState) { 
  super.onCreate(savedInstanceState); 
  this.setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE); 
  setContentView(R.layout.main); 
  picSV = (SurfaceView) findViewById(R.id.picSV); 
  picSV.getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); 
  picSV.getHolder().addCallback(new MyCallback()); 
 } 
 
 private class MyCallback implements Callback{ 
 //我们在SurfaceView创建的时候就要进行打开摄像头、设置预览取景所在的SurfaceView、设置拍照的参数、开启预览取景等操作 
  @Override 
  public void surfaceCreated(SurfaceHolder holder) { 
   try { 
    camera = Camera.open();//打开摄像头 
    camera.setPreviewDisplay(picSV.getHolder());//设置picSV来进行预览取景 
    Parameters params = camera.getParameters();//获取照相机的参数 
    params.setPictureSize(800, 480);//设置照片的大小为800*480 
    params.setPreviewSize(800, 480);//设置预览取景的大小为800*480 
    params.setFlashMode("auto");//开启闪光灯 
    params.setJpegQuality(50);//设置图片质量为50   
    camera.setParameters(params);//设置以上参数为照相机的参数 
    camera.startPreview(); 
   } 
   catch (IOException e) {    //开始预览取景，然后我们就可以拍照了 
    e.printStackTrace(); 
   } 
  } 
  
  @Override 
  public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { 
  } 
  
  @Override 
  public void surfaceDestroyed(SurfaceHolder holder) { 
   //当SurfaceView销毁时，我们进行停止预览、释放摄像机、垃圾回收等工作 
   camera.stopPreview(); 
   camera.release(); 
   camera = null; 
  } 
 } 
 
 public void takepic(View v){ 
  //在我们开始拍照前，实现自动对焦 
  camera.autoFocus(new MyAutoFocusCallback()); 
 } 
 
 private class MyAutoFocusCallback implements AutoFocusCallback{ 
  @Override 
  public void onAutoFocus(boolean success, Camera camera) { 
   //开始拍照 
   camera.takePicture(null, null, null, new MyPictureCallback()); 
  } 
 } 
 
 private class MyPictureCallback implements PictureCallback{ 
  @Override 
  public void onPictureTaken(byte[] data, Camera camera) { 
   try { 
    Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length); 
    Matrix matrix = new Matrix(); 
    matrix.preRotate(90); 
    bitmap = Bitmap.createBitmap(bitmap ,0,0, bitmap.getWidth(), 
            bitmap.getHeight(),matrix,true); 
    strPicPath = 
     Environment.getExternalStorageDirectory()+"/1Zxing/"+System.currentTimeMillis()+".jpg"; 
    FileOutputStream fos = new FileOutputStream( strPicPath ); 
    bitmap.compress(Bitmap.CompressFormat.PNG, 100, fos); 
    fos.close(); 
    Handler mHandler = new Handler(); 
    mHandler.post(mRunnable); 
    camera.startPreview(); 
   } 
   catch (Exception e) { 
    e.printStackTrace(); 
   } 
  } 
 } 
  
 public boolean onTouchEvent (MotionEvent event) 
 { 
  int Action = event.getAction(); 
  if ( 1 == Action ) { 
   camera.autoFocus(new MyAutoFocusCallback1()); 
  } 
  return true; 
 } 
  
 private class MyAutoFocusCallback1 implements AutoFocusCallback { 
  @Override 
  public void onAutoFocus(boolean success, Camera camera) { 
  } 
 } 
  
 @Override 
 public void onResume(){ 
  super.onResume(); 
  //通过OpenCV引擎服务加载并初始化OpenCV类库，所谓OpenCV引擎服务即是 
  //OpenCV_2.4.3.2_Manager_2.4_*.apk程序包，存在于OpenCV安装包的apk目录中 
  OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_10, this, mLoaderCallback); 
 } 
 
 Runnable mRunnable = new Runnable() { 
  public void run() { 
   List contours = new ArrayList(); 
   String strMissingTime = null; 
   Mat srcColor = new Mat(), srcColorResize = new Mat(); 
   Mat srcGray = new Mat(), srcGrayResize = new Mat(), srcGrayResizeThresh = new Mat(); 
   srcGray = Highgui.imread(strPicPath, 0); 
   srcColor = Highgui.imread(strPicPath, 1); 
   Imgproc.resize(srcGray, srcGrayResize, new Size(srcGray.cols()*0.2,srcGray.rows()*0.2)); 
   Imgproc.resize(srcColor, srcColorResize, new Size(srcGray.cols()*0.2,srcGray.rows()*0.2)); 
   long start = System.currentTimeMillis(); 
   //二值化加轮廓寻找 
   Imgproc.adaptiveThreshold(srcGrayResize, srcGrayResizeThresh, 255, 
          Imgproc.ADAPTIVE_THRESH_GAUSSIAN_C, 
          Imgproc.THRESH_BINARY, 35, 5); 
   Imgproc.findContours(srcGrayResizeThresh, contours, new Mat(), 
         Imgproc.RETR_LIST, Imgproc.CHAIN_APPROX_NONE); 
   long end = System.currentTimeMillis(); 
   strMissingTime = String.valueOf( end - start ); 
   strMissingTime = strMissingTime + "\r"; 
   //轮廓绘制 
   for ( int i = contours.size()-1; i >= 0; i-- ) 
   { 
    MatOfPoint2f NewMtx = new MatOfPoint2f( contours.get(i).toArray() ); 
    RotatedRect rotRect = Imgproc.minAreaRect( NewMtx ); 
    Point vertices[] = new Point[4]; 
    rotRect.points(vertices); 
    List rectArea = new ArrayList(); 
    for ( int n = 0; n < 4; n ++ ) 
    { 
     Point temp = new Point(); 
     temp.x = vertices[n].x; 
     temp.y = vertices[n].y; 
     rectArea.add(temp); 
    } 
    Mat rectMat = Converters.vector_Point_to_Mat(rectArea); 
    double minRectArea = Imgproc.contourArea( rectMat ); 
    Point center = new Point(); 
    float radius[] = {0}; 
    Imgproc.minEnclosingCircle(NewMtx, center, radius); 
    if( 
     Imgproc.contourArea( contours.get(i)) < 300 || 
     Imgproc.contourArea( contours.get(i)) > 3000 
     || minRectArea < radius[0]*radius[0]*1.57 
    ) contours.remove(i); 
   } 
   Imgproc.drawContours(srcColorResize, contours, -1, new Scalar(255,0,0)); 
   Highgui.imwrite(Environment.getExternalStorageDirectory()+"/1Zxing/" 
       +System.currentTimeMillis()+"contour.jpg", srcColorResize);   
   File file=new File(Environment.getExternalStorageDirectory()+"/1Zxing/","log.txt"); 
   BufferedWriter out = null; 
   try { 
    out = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file, true))); 
    out.write(strMissingTime); 
    out.close(); 
   } 
   catch (Exception e) { 
    e.printStackTrace(); 
   }    
  } 
 }; 
}