위의 소스로 간단하게 예제 만들어봤습니다. 잘 돌아가는지는 저도 테스트를 많이 안해봤지만 어느정도 돌아가는지 확인은 했습니다.

private HashSet<String> mBucketDispalyList;
private ArrayList<String> mFolderArrayList;

private ListView mListView;
private ListAdapter mListAdapter;
private Context mContext;

private static final String[] PROJECTION = new String[] { 
        MediaStore.Images.Media._ID,
        MediaStore.Images.Media.BUCKET_DISPLAY_NAME, 
        MediaStore.Images.Media.DATA,
        MediaStore.Images.Media.TITLE};

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    mContext = this;
    mListView = (ListView) findViewById(R.id.view_list);

    mBucketDispalyList = new HashSet<String>();

}

@Override
protected void onResume() {
    // TODO Auto-generated method stub
    super.onResume();
    getBucketDisplayList();
    if (DEBUG) {
        Iterator<String> iterator = mBucketDispalyList.iterator();

        while (iterator.hasNext()) {
            Log.e(TAG, "hashset : " + iterator.next());
        }
    }
    mFolderArrayList = new ArrayList<String>(mBucketDispalyList);
    mListAdapter = new ListAdapter();
    mListAdapter.setData(mFolderArrayList);
    mListView.setAdapter(mListAdapter);
    mListView.setOnItemClickListener(this);
}

public void getBucketDisplayList() {
    String bucket, dataPath;
    Cursor cursor = getContentResolver().query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, PROJECTION, null, null, null);

    if (cursor != null && cursor.moveToFirst()) {

        int bucketColumn = cursor.getColumnIndex(MediaStore.Images.Media.BUCKET_DISPLAY_NAME);
        int dataPathColumn = cursor.getColumnIndex(MediaStore.Images.Media.DATA);
        do {
            bucket = cursor.getString(bucketColumn);
            dataPath = cursor.getString(dataPathColumn);
            Log.d(TAG, "bucketColumn : " + bucket);
            mBucketDispalyList.add(bucket.toString());
            Log.e(TAG, "bucket = " + bucket + " , dataPath = " + dataPath);
        } while (cursor.moveToNext());

        cursor.close();
    }
}

public ArrayList<String> getPictureList(String bucket) {
    String title = null;
    ArrayList<String> pictureList = new ArrayList<String>();
    String selection = MediaStore.Images.Media.BUCKET_DISPLAY_NAME  + " == " + "\""+bucket+"\"";
    Cursor cursor = getContentResolver().query(Images.Media.EXTERNAL_CONTENT_URI, PROJECTION, selection, null, null);

    if (cursor != null && cursor.moveToFirst()) {

        int titleColumn = cursor.getColumnIndex(MediaStore.Images.Media.TITLE);
        do {
            title = cursor.getString(titleColumn);
            Log.d(TAG, "title : " + title);
            pictureList.add(title.toString());
        } while (cursor.moveToNext());

        cursor.close();
    }

    return pictureList;
}