MainActivity.java

private Bitmap uriToBitmap(Uri uri){
        Bitmap bitmap = null;

        try {
            bitmap = MediaStore.Images.Media.getBitmap(getContentResolver() , uri);
        } catch (IOException exception) {
            exception.printStackTrace();
            Toast.makeText(this, "Error", Toast.LENGTH_SHORT).show();
        }

        return bitmap;
    }

    private Uri convertImageViewToUri(ImageView imageView, String filename) {

        OutputStream imageOutStream;
        Uri uri = null;
        Bitmap imageBitmap = ((BitmapDrawable) imageView.getDrawable()).getBitmap();

        try {

            // create path
            final String createPath = getExternalFilesDir(null).getAbsolutePath() + "/" + filename;

            imageOutStream = new FileOutputStream(createPath);

            // saving Bitmap
            imageBitmap.compress(Bitmap.CompressFormat.JPEG, 100, imageOutStream);
            imageOutStream.close(); //  close output stream

            uri = Uri.fromFile(new File(createPath));
        } catch (IOException e) {
            e.printStackTrace();
            Toast.makeText(this, "Something went wrong!!", Toast.LENGTH_SHORT).show();
        }

        return uri;
    }