1. Imaged Document Text Retrieval without OCR IEEE Trans. on PAMI vol.24, no.6 June, 2002 報告人：周遵儒

2. Outline  Introduction  HTD and VTD  Class of Character Objects  Similarity Measure of Documents  Experimental Results  Conclusions

3. Introduction  Retrieval of Imaged Documents  Process with OCR v.s. without OCR  Language dependence v.s. language independence

4. Procedure  Image Preprocessing  Feature extraction of character objects  Horizontal Traverse Density (HTD)  Vertical Traverse Density (VTD)  Clustering  To Identify classes of character objects  Document representation  Hash Table  N-Gram  To construct indexes for imaged document retrieval

5. Features: HTD and VTD

6. Class of Character Objects  Unsupervise Clustering with HTD and VTD  Distance measure of character objects

7. Distance Measure of Character Objects

8. Examples of Character Objects

9. Similarity Measure of Documents  N-Gram Algorithm  Cosine angle between two documents

10. Corpus  UW1 database (600 dpi)

11. Experimental Results  Corpus I  E01-E26

12. Experimental Results  Corpus II

13. Experimental Results

17. Conclusion and Future Work  A new method for image document retrieval without OCR  Retrieval of language independence  Improvement of robustness for different fonts and noisy documents