Android - Hide album art from image gallery activity

Question

I've made an image gallery activity that is needed for my app. All works well except that it shows an image album for every music album I have in my SD card that contains album art. The default gallery app manages to hide these albums-pictures. How can I achieve the same ?

I get image albums with this code:

    Uri uri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
    String[] projection = { MediaStore.Images.Media._ID, MediaStore.Images.Media.BUCKET_ID,
            MediaStore.Images.Media.BUCKET_DISPLAY_NAME,MediaStore.Images.Media.DATA };
    Cursor cursor = getContentResolver().query(uri, projection, null, null, null);
    ArrayList<String> ids = new ArrayList<String>();
    if (cursor != null) {
        while (cursor.moveToNext()) {
            PhotoAlbum album = new PhotoAlbum();
            int columnIndex = cursor.getColumnIndex(MediaStore.Images.Media.BUCKET_ID);
            album.id = cursor.getString(columnIndex);

            if (!ids.contains(album.id)) {
                //get album name
                columnIndex = cursor.getColumnIndex(MediaStore.Images.Media.BUCKET_DISPLAY_NAME);
                album.name = cursor.getString(columnIndex);
                //get image id for the album cover
                columnIndex = cursor.getColumnIndex(MediaStore.Images.Media._ID);
                album.coverID = cursor.getInt(columnIndex);
                //get filename of album cover image
                columnIndex = cursor.getColumnIndex(MediaStore.Images.Media.DATA);
                album.fileName=new File(cursor.getString(columnIndex)).getParentFile().getAbsolutePath(); 
                album.count++;     albumList.add(album);      ids.add(album.id);    album.bm=null;


            } else { albumList.get(ids.indexOf(album.id)).count++; }
        }
        cursor.close();
    }