Searched on Google with the first line of a JAVA stack trace?

We can recommend more relevant solutions and speed up debugging when you paste your entire stack trace with the exception message. Try a sample exception.

Recommended solutions based on your search

Solutions on the web

via Stack Overflow by Ayush Panda
, 1 year ago
) descriptorType = "BRISK"; System.out.println(descriptorType); tv.setText("Select the two images to be compared.\n" + "DescriptorExtractor:" + descriptorType + "\nHamming distance between descriptors:" + min_dist + "\nMinimum number of good
LoaderCallbackInterface.SUCCESS: {
                Log.i(TAG, "OpenCV loaded successfully");
            }
            break;
            default: {
                super.onManagerConnected(status);
            }
            break;
        }
    }
};
@Override
protected void onCreate(Bundle savedInstanceState) {
    Log.i(TAG, "called onCreate");
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    iv1 = (ImageView) MainActivity.this.findViewById(R.id.img1);
    iv2 = (ImageView) MainActivity.this.findViewById(R.id.img2);
    start = (Button) MainActivity.this.findViewById(R.id.button1);
    tv = (TextView) MainActivity.this.findViewById(R.id.tv);
    run();
}
public void run() {
    if (descriptor == DescriptorExtractor.BRISK)
        descriptorType = "BRISK";
    System.out.println(descriptorType);
    tv.setText("Select the two images to be compared.\n" + "DescriptorExtractor:" + descriptorType + "\nHamming distance between descriptors:" + min_dist + "\nMinimum number of good matches:" + min_matches);
    iv1.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View arg0) {
            Intent photoPickerIntent = new Intent(Intent.ACTION_PICK);
            photoPickerIntent.setType("image/*");
            startActivityForResult(photoPickerIntent, SELECT_PHOTO);
            imgNo = 1;
        }
    });
    iv2.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View arg0) {
            Intent photoPickerIntent = new Intent(Intent.ACTION_PICK);
            photoPickerIntent.setType("image/*");
            startActivityForResult(photoPickerIntent, SELECT_PHOTO);
            imgNo = 2;
        }
    });
    start.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View arg0) {
            // TODO Auto-generated method stub
            if (bmpimg1 != null && bmpimg2 != null) {
                bmpimg1 = Bitmap.createScaledBitmap(bmpimg1, 100, 100, true);
                bmpimg2 = Bitmap.createScaledBitmap(bmpimg2, 100, 100, true);
                Mat img1 = new Mat();
                Utils.bitmapToMat(bmpimg1, img1);
                Mat img2 = new Mat();
                Utils.bitmapToMat(bmpimg2, img2);
                Imgproc.cvtColor(img1, img1, Imgproc.COLOR_RGBA2GRAY);
                Imgproc.cvtColor(img2, img2, Imgproc.COLOR_RGBA2GRAY);
                img1.convertTo(img1, CvType.CV_32F);
                img2.convertTo(img2, CvType.CV_32F);
                //Log.d("ImageComparator", "img1:"+img1.rows()+"x"+img1.cols()+" img2:"+img2.rows()+"x"+img2.cols());
                Mat hist1 = new Mat();
                Mat hist2 = new Mat();
                MatOfInt histSize = new MatOfInt(180);
                MatOfInt channels = new MatOfInt(0);
                ArrayList<Mat> bgr_planes1 = new ArrayList<Mat>();
                ArrayList<Mat> bgr_planes2 = new ArrayList<Mat>();
                Core.split(img1, bgr_planes1);
                Core.split(img2, bgr_planes2);
                MatOfFloat histRanges = new MatOfFloat(0f, 180f);
                boolean accumulate = false;
                Imgproc.calcHist(bgr_planes1, channels, new Mat(), hist1, histSize, histRanges, accumulate);
                Core.normalize(hist1, hist1, 0, hist1.rows(), Core.NORM_MINMAX, -1, new Mat());
                Imgproc.calcHist(bgr_planes2, channels, new Mat(), hist2, histSize, histRanges, accumulate);
                Core.normalize(hist2, hist2, 0, hist2.rows(), Core.NORM_MINMAX, -1, new Mat());
                img1.convertTo(img1, CvType.CV_32F);
                img2.convertTo(img2, CvType.CV_32F);
                hist1.convertTo(hist1, CvType.CV_32F);
                hist2.convertTo(hist2, CvType.CV_32F);
                double compare = Imgproc.compareHist(hist1, hist2, Imgproc.CV_COMP_CHISQR);
                Log.d("ImageComparator", "compare: " + compare);
                if (compare > 0 && compare < 1500) {
                    Toast.makeText(MainActivity.this, "Images may be possible duplicates, verifying", Toast.LENGTH_LONG).show();
                    new asyncTask(MainActivity.this).execute();
                } else if (compare == 0)
                    Toast.makeText(MainActivity.this, "Images are exact duplicates", Toast.LENGTH_LONG).show();
                else
                    Toast.makeText(MainActivity.this, "Images are not duplicates", Toast.LENGTH_LONG).show();
                startTime = System.currentTimeMillis();
            } else
                Toast.makeText(MainActivity.this,
                        "You haven't selected images.", Toast.LENGTH_LONG)
                        .show();
        }
    });
}
@Override
protected void onNewIntent(Intent newIntent) {
    super.onNewIntent(newIntent);
    min_dist = newIntent.getExtras().getInt("min_dist");
    descriptor = newIntent.getExtras().getInt("descriptor");
    min_matches = newIntent.getExtras().getInt("min_matches");
    run();
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent imageReturnedIntent) {
    super.onActivityResult(requestCode, resultCode, imageReturnedIntent);
    switch (requestCode) {
        case SELECT_PHOTO:
            if (resultCode == RESULT_OK) {
                selectedImage = imageReturnedIntent.getData();
                try {
                    imageStream = getContentResolver().openInputStream(
                            selectedImage);
                } catch (FileNotFoundException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                yourSelectedImage = BitmapFactory.decodeStream(imageStream);
                if (imgNo == 1) {
                    iv1.setImageBitmap(yourSelectedImage);
                    path1 = selectedImage.getPath();
                    bmpimg1 = yourSelectedImage;
                } else if (imgNo == 2) {
                    iv2.setImageBitmap(yourSelectedImage);
                    path2 = selectedImage.getPath();
                    bmpimg2 = yourSelectedImage;
                }
            }
    }
}
@Override
public void onPause() {
    super.onPause();
}
@Override
public void onResume() {
    super.onResume();
    OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_4, this, mLoaderCallback);
}
public static class asyncTask extends AsyncTask<Void, Void, Void> {
    private static Mat img1, img2, descriptors, dupDescriptors;
    private static FeatureDetector detector;
    private static DescriptorExtractor DescExtractor;
    private static DescriptorMatcher matcher;
    private static MatOfKeyPoint keypoints, dupKeypoints;
    private static MatOfDMatch matches, matches_final_mat;
    private static Bitmap bmp, bmpimg1, bmpimg2;
    private static ProgressDialog pd;
    private static TextView tv;
    private static int descriptor = DescriptorExtractor.BRISK;
    private static int min_matches = 750;
    private static int min_dist = 10;
    private static long endTime;
    private static boolean isDuplicate = false;
    private MainActivity asyncTaskContext = null;
    private static Scalar RED = new Scalar(255, 0, 0);
    private static Scalar GREEN = new Scalar(0, 255, 0);
    public asyncTask(MainActivity context) {
        asyncTaskContext = context;
    }
    @Override
    protected void onPreExecute() {
        pd = new ProgressDialog(asyncTaskContext);
        pd.setIndeterminate(true);
        pd.setCancelable(true);
        pd.setCanceledOnTouchOutside(false);
        pd.setMessage("Processing...");
        pd.show();
    }
    @Override
    protected Void doInBackground(Void... arg0) {
        // TODO Auto-generated method stub
        compare();
        return null;
    }
    @Override
    protected void onPostExecute(Void result) {
        try {
            Mat img3 = new Mat();
            MatOfByte drawnMatches = new MatOfByte();
            Features2d.drawMatches(img1, keypoints, img2, dupKeypoints,
                    matches_final_mat, img3, GREEN, RED, drawnMatches, Features2d.NOT_DRAW_SINGLE_POINTS);
            bmp = Bitmap.createBitmap(img3.cols(), img3.rows(),
                    Bitmap.Config.ARGB_8888);
            Imgproc.cvtColor(img3, img3, Imgproc.COLOR_BGR2RGB);
            Utils.matToBitmap(img3, bmp);
            List<DMatch> finalMatchesList = matches_final_mat.toList();
            endTime = System.currentTimeMillis();
            if (finalMatchesList.size() > min_matches)// dev discretion for
            // number of matches to
            // be found for an image
            // to be judged as
            // duplicates or not
            {
                tv.setText(finalMatchesList.size()
                        + " matches were found. Possible duplicate image.\nTime taken="
                        + (endTime - startTime) + "ms");
                isDuplicate = true;
            } else {
                tv.setText(finalMatchesList.size()
                        + " matches were found. Images aren't similar.\nTime taken="
                        + (endTime - startTime) + "ms");
                isDuplicate = false;
            }
            pd.dismiss();
        } catch (Exception e) {
            e.printStackTrace();
            Toast.makeText(asyncTaskContext, e.toString(),
                    Toast.LENGTH_LONG).show();
        }
    }
    void compare() {
        try {
            bmpimg1 = bmpimg1.copy(Bitmap.Config.ARGB_8888, true);
            bmpimg2 = bmpimg2.copy(Bitmap.Config.ARGB_8888, true);
            img1 = new Mat();
            img2 = new Mat();
            Utils.bitmapToMat(bmpimg1, img1);
            Utils.bitmapToMat(bmpimg2, img2);
            Imgproc.cvtColor(img1, img1, Imgproc.COLOR_BGR2RGB);
            Imgproc.cvtColor(img2, img2, Imgproc.COLOR_BGR2RGB);
            detector = FeatureDetector.create(FeatureDetector.PYRAMID_FAST);
            DescExtractor = DescriptorExtractor.create(descriptor);
            matcher = DescriptorMatcher
                    .create(DescriptorMatcher.BRUTEFORCE_HAMMING);
            keypoints = new MatOfKeyPoint();
            dupKeypoints = new MatOfKeyPoint();
            descriptors = new Mat();
            dupDescriptors = new Mat();
            matches = new MatOfDMatch();
            detector.detect(img1, keypoints);
            Log.d("LOG!", "number of query Keypoints= " + keypoints.size());
            detector.detect(img2, dupKeypoints);
            Log.d("LOG!", "number of dup Keypoints= " + dupKeypoints.size());
            // Descript keypoints
            DescExtractor.compute(img1, keypoints, descriptors);
            DescExtractor.compute(img2, dupKeypoints, dupDescriptors);
            Log.d("LOG!", "number of descriptors= " + descriptors.size());
            Log.d("LOG!",
                    "number of dupDescriptors= " + dupDescriptors.size());
            // matching descriptors
            matcher.match(descriptors, dupDescriptors, matches);
            Log.d("LOG!", "Matches Size " + matches.size());
            // New method of finding best matches
            List<DMatch> matchesList = matches.toList();
            List<DMatch> matches_final = new ArrayList<DMatch>();
            for (int i = 0; i < matchesList.size(); i++) {
                if (matchesList.get(i).distance <= min_dist) {
                    matches_final.add(matches.toList().get(i));
                }
            }
            matches_final_mat = new MatOfDMatch();
            matches_final_mat.fromList(matches_final);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}
 } Also. What exactly is a NullPointerException and how do I prevent it. Sorry if there isn't enough details, this is my first post on this forum. And what confuses me is the logcat: 09-11 19:32:14.998 1506-3141/duketip.comparatortest W/System.err: java.lang.NullPointerException 09-11 19:32:14.998 1506-3141/duketip.comparatortest W/System.err: at duketip.comparatortest.MainActivity$asyncTask.compare(MainActivity.java:337) 09-11 19:32:14.998 1506-3141/duketip.comparatortest W/System.err: at duketip.comparatortest.MainActivity$asyncTask.doInBackground(MainActivity.java:292) 	at duketip.comparatortest.MainActivity$asyncTask.doInBackground(MainActivity.java:256)	at android.os.AsyncTask$2.call(AsyncTask.java:288)	at java.util.concurrent.FutureTask.run(FutureTask.java:237)