A hierarchical, HMM-based automatic evaluation of OCR accuracy for a digital library of books

A number of projects are creating searchable digital libraries of printed books. These include the Million Book Project, the Google Book project and similar efforts from Yahoo and Microsoft. Content-based on line book retrieval usually requires first converting printed text into machine readable (e.g. ASCII) text using an optical character recognition (OCR) engine and then doing full text search on the results. Many of these books are old and there are a variety of processing steps that are required to create an end to end system. Changing any step (including the scanning process) can affect OCR performance and hence a good automatic statistical evaluation of OCR performance on book length material is needed. Evaluating OCR performance on the entire book is non-trivial. The only easily obtainable ground truth (the Gutenberg e-texts) must be automatically aligned with the OCR output over the entire length of a book. This may be viewed as equivalent to the problem of aligning two lar...

• Type: Conference
• Year: 2006
• Where: JCDL
• Authors: Shaolei Feng, R. Manmatha
• Keywords: Book Project, JCDL 2006, OCR Output, OCR Performance