DRR Research beyond COTS OCR Software: A Survey

After decades of research, Optical Character Recognition (OCR) has entered into a relatively mature stage. Commercial off-the-shelf (COTS) OCR software packages have become powerful tools in Document Recognition and Retrieval (DRR) applications. One question naturally arises: What areas are left for new DRR research beyond COTS OCR software? There are many discussions around it in recent conferences. This paper attempts to address this question through a systematic survey of recently reported DRR projects as well as our own Digital Content Re-Mastering (DCRM) research at HP Labs. This survey has shown that custom DRR research is still in great need for better accuracy and reliability, complementary contents, or downstream information retrieval. Several concrete observations are also made on the basis of this survey: First, the basic character/word recognition is mostly taken on by COTS software, with a few exceptions. Second, system-level research with regard to reliability and guaranteed accuracy can seldom be replaced by COTS software. Third, document-level structure understanding still has much room to expand. Fourth, postOCR information retrieval also has many challenging research topics.