Providing Access to Old Greek Documents Using Keyword Spotting Techniques

Keyword spotting is an alternative methodology for document indexing based on spotting words directly on images without the use of a character recognition system. In this paper, an overview of recent techniques and available databases for keyword spotting is presented focusing on the specific characteristics of old Greek machine-printed and handwritten documents. These documents are import treasures of cultural heritage and a valuable source of information for scholars. Indexing of such content is a very challenging task considering the additional problem of having many character classes as well as a variety of different diacritic mark combinations that may appear above or below Greek characters. All steps of a keyword spotting system are highlighted, namely, preprocessing for image binarization, enhancement and segmentation, feature representation, matching and word retrieval, in order to report the efficiency of current keyword spotting approaches when applied to old Greek documents.