My personal research over the last twenty years has focused on these topics:

• image understanding theory, algorithms, and systems;
• high-performance, trainable, and adaptive computer-vision system architectures;
• model-directed classification, recognition, and analysis methodologies;
• multi-media digital libraries;
• document analysis and recognition algorithms; and
• cognition-based Web security protocols.

At present, I am actively investigating these topics:

1. Document image content extraction (DICE);
2. Human Interactive Proofs and CAPTCHAs;
   
3. Full integration of document images into digital libraries; and
   
4. High-performance image understanding systems.