1. Introduction
Local government document are of great historical values. These documents would benefit from being available in digital form. Once converted to electronic form, the documents can be used in digital libraries or for wider diffusion on the Internet. To increase efficiency of paperwork processing and to better utilize the content of data originating in paper form, not only must the paper document be converted to images of the documents in electronic form, but these digital copies must also be converted to a computer-readable format. In fact, the quality of these digital copies depends greatly on the quality of the original heritage documents that are often affected by several types of degradations. Old documents, supported by fragile materials, are easily affected by bad environmental conditions as the time elapses. Manipulation, humidity and unfitted storage for many years affect heritage documents and make them difficult to read. The deterioration level increases with excessive manipulations and consultations of the ancient document. Moreover, digitizing techniques inevitably add up, during the scanning process, some degradation to the quality of the images taken for the documents. The actual state of the readability of the digital copy of the degraded document is very bad. Hence appears the need to define techniques to improve the readability and accessibility by resorting to restoration techniques.