Android Extract EXIF metadata from byte[] data

Question

I have a custom camera application. I need metadata of Image captured by the custom camera. I saved the byte data before decodebytearray (Constant.imageData1 = data;) and save it to a constant class with type byte and before using this byte data I converted it to string. When I going to execute it with ExifInterface and show it to log, then the application crashes.

Here is my OnPictureTaken Method:

PictureCallback mPicture = new PictureCallback() {
    @Override
    public void onPictureTaken(byte[] data, Camera camera) {
        Constant.imageData1 = data;
        Log.e("Camrera", "22222222222222222");
        BitmapFactory.Options bfo = new BitmapFactory.Options();
        bfo.inDither = false;
        // bfo.inJustDecodeBounds = true;
        bfo.inPurgeable = true;
        bfo.inTempStorage = new byte[16 * 1024];

        Intent intent = new Intent(context, PreviewActivity.class);
        // intent.putExtra("data", data);
        Bitmap bitmapPicture = BitmapFactory.decodeByteArray(data, 0,
                data.length, bfo);
        Matrix matrix = new Matrix();
        if (Constant.result == 180) {
            matrix.postRotate(270);
        }
        if (Constant.result == 270) {
            matrix.postRotate(180);
        }
        int height = bitmapPicture.getHeight();
        int width = bitmapPicture.getWidth();
        //Bitmap scaledBitmap = Bitmap.createScaledBitmap(bitmapPicture,
                //height, width, true);
        Bitmap rotatedBitmap = Bitmap.createBitmap(bitmapPicture, 0, 0,
                bitmapPicture.getWidth(), bitmapPicture.getHeight(), matrix,
                true);
        ByteArrayOutputStream blob = new ByteArrayOutputStream();
        Log.e("Camrera1", "22222222222222222");
        rotatedBitmap.compress(CompressFormat.JPEG,
                50 /* ignored for PNG */, blob);
        byte[] bitmapdata = blob.toByteArray();
        Constant.imageData = bitmapdata;
        Log.e("Camrera2", "22222222222222222");
        startActivity(intent);

    }
};

Here is my execution code:

private void SaveImage() {
    try {
        String data = byteArrayToString(Constant.imageData1);
        ExifInterface ex = new ExifInterface(data);
        String make = ex.getAttribute(ExifInterface.TAG_MAKE);
        Log.e("Make", make);
        Log.e("Make", make);
        Log.e("Make", make);
        finish();

    } catch (Exception e) {
            e.printStackTrace();
        }
}

And the bytearraytostring method is:

public static String byteArrayToString(byte[] bytes)
{
    return new String(bytes);
}

This is very important to me. Please help me.

Answer 1

Please try the code snippet below, and change it where you need to. Warning: I haven't tested it.

So, basically, what I did is this:

• Step 1. Get the byte array from the camera in the onPictureTaken method.
• Step 2. Create a file on the SDCard and write the byte array to the file

• Step 3. Read Exif Metadata from File-Path

  @Override
  public void onPictureTaken(byte[] data, Camera camera) {
  
      //Step 1. Create file for storing image data on SDCard
      File sdDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
      File pictureFileDir = new File(sdDir, "RDCCameraImages");
  
      if (!pictureFileDir.exists() && !pictureFileDir.mkdirs()) {
  
        Log.d(TAG, "Can't create directory to save image.");
        return;
  
      }
  
      //Step 2. write image byte array to file
      String photoFile = "Picture_" + date + ".jpg";
      String imageFilePath = pictureFileDir.getPath() + File.separator + photoFile;
      File pictureFile = new File(imageFilePath);
  
      try 
      {
            FileOutputStream fos = new FileOutputStream(pictureFile);
            fos.write(data);
            fos.close();
            Toast.makeText(context, "New Image saved:" + photoFile,
                Toast.LENGTH_LONG).show();
          } catch (Exception error) {
            Log.d(TAG, "File" + filename + "not saved: "
                + error.getMessage());
            Toast.makeText(context, "Image could not be saved.",
                Toast.LENGTH_LONG).show();
      }           
      //Step 3. Get Exif Info from File path
      ExifInterface exif;
      try {
          exif = new ExifInterface(imageFilePath);
          String make = exif.getAttribute(ExifInterface.TAG_MAKE);
  
      } catch (IOException e) {
          e.printStackTrace();
      }
  
      //check the value of  “make” here
  

  }