2-D strings is one of a few representation structures originally designed for use in an IDB environment. In this paper, we propose a generalized approach for 2-D string based indexing which avoids the exhaustive search through the entire database of previous 2-D strings based techniques. The classical framework of representation of 2-D strings is also specialized to the cases of scaled and unscaled images. Then, index structures for supporting retrieval by content utilizing the 2-D string representation framework are discussed. The performance of the proposed method is evaluated using a database of simulated images and compared with the performance of existing techniques of 2-D string indexing and retrieval. The results demonstrate a very significant improvement in retrieval performance.