public void checkForNewImages() {
   // Here we'll only check for newer images
   final String[] columns = {MediaStore.Images.Thumbnails._ID};
   final String orderBy = MediaStore.Images.Media._ID;
   Cursor imagecursor =
       managedQuery(
           MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
           columns,
           MediaStore.Images.Media._ID + " > " + lastId,
           null,
           orderBy);
   int image_column_index = imagecursor.getColumnIndex(MediaStore.Images.Media._ID);
   int count = imagecursor.getCount();
   for (int i = 0; i < count; i++) {
     imagecursor.moveToPosition(i);
     int id = imagecursor.getInt(image_column_index);
     ImageItem imageItem = new ImageItem();
     imageItem.id = id;
     lastId = id;
     imageItem.img =
         MediaStore.Images.Thumbnails.getThumbnail(
             getApplicationContext().getContentResolver(),
             id,
             MediaStore.Images.Thumbnails.MICRO_KIND,
             null);
     imageItem.selection = true; // newly added item will be selected by default
     images.add(imageItem);
   }
   imagecursor.close();
   notifyDataSetChanged();
 }