private class Test extends AsyncTask<Void,Void,Void>{

@Override
protected Void doInBackground(Void... voids) {


    Bitmap m = loadBitmapFromView(l);

    replaceColor(m,Color.BLACK, Color.WHITE);

    ImageView i = findViewById(R.id.bm);
    String root = Environment.getExternalStorageDirectory().toString();
    File myDir = new File(root + "/req_images");
    myDir.mkdirs();
    int n = 1;
    String fname = "Image-" + n + ".jpg";
    File file = new File(myDir, fname);
    Log.i(TAG, "" + file);
    if (file.exists())
        file.delete();
    try {
        FileOutputStream out = new FileOutputStream(file);
        m.compress(Bitmap.CompressFormat.JPEG, 100, out);
        out.flush();
        out.close();
    } catch (Exception e) {
        e.printStackTrace();
    }

    mFiles.add(file.getPath());

    return null;
}

@Override
protected void onPostExecute(Void aVoid) {
    super.onPostExecute(aVoid);
    mBtnPrint.setEnabled(true);
}

public static Bitmap loadBitmapFromView(View v) {


    if (v.getMeasuredHeight() <= 0) {
        v.measure(WindowManager.LayoutParams.WRAP_CONTENT, WindowManager.LayoutParams.MATCH_PARENT);
        Bitmap b = Bitmap.createBitmap(v.getMeasuredWidth(), v.getMeasuredHeight(), Bitmap.Config.ARGB_8888);
        Canvas c = new Canvas(b);
        v.layout(0, 0, v.getMeasuredWidth(), v.getMeasuredHeight());
        v.draw(c);
        return b;
    }

    Bitmap b = Bitmap.createBitmap( v.getLayoutParams().width, v.getLayoutParams().height, Bitmap.Config.ARGB_8888);
    Canvas c = new Canvas(b);
    v.layout(v.getLeft(), v.getTop(), v.getRight(), v.getBottom());
    v.draw(c);


    return b;
}