Abstract:
The amount of digital information around us has witnessed a remarkable growth during the last
two decades and almost every type of information can be accessed within a span of few clicks.
Like other sources, paper documents have also been digitized facilitating rapid access to the
readers. This digitization of documents and books is only effective if it is complemented by a
search mechanism allowing users retrieve the desired content. This led to a tremendous research
in Optical Character Recognition (OCR) systems which convert document images into text
allowing search and retrieval facility. Although OCR has been established research area for
many years, for many scripts, OCR systems are either non-existent or in early days of research.
In some cases, recognition of text is very challenging due to complexity of script. To address
these issues, Word Spotting allows retrieving the document containing occurrence of provided
query word by matching the shape of words without any knowledge on the semantics. This work
present a word spotting based indexing and retrieval system for digitized English documents.
The document image with English text is segmented into ligatures and each ligature is
represented by a set of features. Clustering of ligature is then carried out to group ligature into
cluster. For indexing, a document is segmented into ligature and each ligature is classified into
one of the ligature classes. An index file is maintained for each cluster which stores all
occurrences (locations) of the ligature in the given document. During the retrieval phase, a
query word presented to the systems is segmented into ligature and each ligature is matched with
the existing clusters. Finally, for each ligature in the query word, the document containing the
occurrences of the ligature are retrieved using the index file.
