opencv安卓人脸识别

Question

这是我从http://www.java2s.com/Open-Source/Android_Free_Code/Facebook/Download_Free_code_face_recognition.htm.

package face_recognition;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.util.LinkedList;
import org.opencv.android.Utils;
import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.core.Rect;
import org.opencv.core.Scalar;
import org.opencv.objdetect.CascadeClassifier;
import com.face_recognition.R;
import com.googlecode.javacpp.Loader;
import com.googlecode.javacv.cpp.opencv_objdetect;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.util.Log;
import android.widget.ImageView;
public class ImageRecognitionActivity extends Activity {
private Mat imageMat;
private FacebookImage facebookImage = null;
private Context context=this;
private ImageView imageView; 
private Bitmap fbImage;
private CascadeClassifier mCascade;
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.view3_layout);
    imageView = (ImageView) findViewById(R.id.imageview);
    Intent intent = getIntent();   
    Bundle b = intent.getExtras();  
    String chosenImageUrl = (String) b.get("chosenImageUrl");   
    try {                           
        facebookImage = new FacebookImage(chosenImageUrl);    
        fbImage = facebookImage.getPicture(); 

       imageMat =                 org.opencv.android.Utils.bitmapToMat(fbImage.copy(Bitmap.Config.ARGB_8888,true)); 

注意：//我在这条线上弄错了。它说它需要一个垫子，一旦我加上它，它就说不能//从垫子变成虚空。。我该如何解决此问题？

    } catch (MalformedURLException e) { /* ... */ e.printStackTrace();
    } catch (IOException e)     { /* ... */ e.printStackTrace();
    }
    Loader.load(opencv_objdetect.class);  
    try {
        InputStream is = context.getResources().openRawResource(R.raw.haarcascade_frontalface_alt);
        File cascadeDir = context.getDir("cascade", Context.MODE_PRIVATE);
        File cascadeFile = new File(cascadeDir, "lbpcascade_frontalface.xml");
        FileOutputStream os = new FileOutputStream(cascadeFile);
        byte[] buffer = new byte[4096];
        int bytesRead;
        while ((bytesRead = is.read(buffer)) != -1) {
            os.write(buffer, 0, bytesRead);
        }
        is.close();
        os.close();
        mCascade = new CascadeClassifier(cascadeFile.getAbsolutePath());
        if (mCascade.empty()) {
                Log.e("TAG", "Failed to load cascade classifier");
                mCascade = null;
        } else
            Log.i("TAG", "Loaded cascade classifier from " + cascadeFile.getAbsolutePath());
        cascadeFile.delete();
        cascadeDir.delete();
    } catch (IOException e) {
        e.printStackTrace();
        Log.e("TAG", "Failed to load cascade. Exception thrown: " + e);
    }
    LinkedList<Rect> facesdetection = new LinkedList<Rect>();
    mCascade.detectMultiScale(imageMat, facesdetection);
    Bitmap imageBitmap = null;
    for (Rect r : facesdetection){  
        Core.rectangle(imageMat, r.tl(), r.br(), new Scalar(0, 255, 0, 255), 2); 
    }
    imageBitmap = Bitmap.createBitmap(imageMat.cols(), imageMat.rows(), Bitmap.Config.ARGB_8888);
    Utils.matToBitmap(imageMat, imageBitmap);
    imageView.setImageBitmap(imageBitmap); 
}

}

Answer 1

bitmapToMat不返回任何内容。您必须将结果Mat作为参数传递，如下所示：

imageMat = new Mat();
org.opencv.android.Utils.bitmapToMat(fbImage.copy(Bitmap.Config.ARGB_8888,true), imageMat);