Converting image to string using the Base64 algorithm

I am new to android. I am trying to capture the image and store it in firebase. Since we need to convert the image to string and then store it in firebase, I am using the base64 algorithm.

The methods for capturing image and storing it in the database is :

public void capturePhoto(View v) {
        Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        startActivityForResult(intent, CAMERA_REQUEST);
    }

    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode == CAMERA_REQUEST && resultCode == RESULT_OK) {
            Bitmap photo = (Bitmap) data.getExtras().get("data");

            ImageView imageView = (ImageView) findViewById(R.id.imageView);
            imageView.setImageBitmap(photo);

        }
    }

    public void storeDatabase(View v)
    {
        EditText editRollno = (EditText) findViewById(R.id.rollno);
        EditText editname = (EditText) findViewById(R.id.name);
        EditText editmarks = (EditText) findViewById(R.id.marks);
        Firebase ref1 = ref.child("student_information").child("Student" + n);
        ref1.child("Name").setValue(editname.getText().toString());
        ref1.child("Rollno").setValue(editRollno.getText().toString());
        ref1.child("Marks").setValue(editmarks.getText().toString());
        Bitmap bmp = BitmapFactory.decodeResource(getResources(), R.drawable.abc);//your image
        ByteArrayOutputStream bYtE = new ByteArrayOutputStream();
        bmp.compress(Bitmap.CompressFormat.PNG, 100, bYtE);
        bmp.recycle();
        byte[] byteArray = bYtE.toByteArray();
        imageFile = Base64.encodeToString(byteArray, Base64.DEFAULT);
        ref1.child("Image").setValue(imageFile);
        n++;
}

When I click on the submit button, it takes a lot of time to upload the values. Moreover, many a times I can see the line

Skipped 537 frames!  The application may be doing too much work on its main thread.

in the Android Monitor.

If I comment the image processing lines, it is working all fine. Can somebody please tell me how to avoid such error so that the image is uploaded instantly in my database.