private File getOutputMediaFile() {

        String state = Environment.getExternalStorageState();
        Assert.assertTrue("external media is mounted", TextUtils.equals(state, Environment.MEDIA_MOUNTED));

        File mediaStorageDir;
        mediaStorageDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);

        String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
        File mediaFile;
        mediaFile = new File(mediaStorageDir.getPath() + File.separator +
                "IMG_" + timeStamp + ".jpg");
        return mediaFile;
    }