Processing of low quality document images: Issues and directions

Issues facing document image analysis and recognition are discussed based on the quality and complexity of images. Special attention is paid to low-quality images of ancient manuscripts. Because of the complex content of this type of document, which usually contains several layers of information in the same scale levels, the definition of degradation must be reconsidered. This opens up new challenges for the modeling of document degradation. Also, discussed is the development of appropriate restoration methods for handling degradation. The advantages of preprocessing a document to remove some of the unwanted layers of information in the document image in order to improve its quality are considered, using currently available or new paradigms.