International Journal of Advanced Engineering, Management and Science (IJAEMS) [Vol-1, Issue-8, Nov- 2015] Infogain Publication (Infogainpublication.com ) ISSN : 2454-1311 Ijaems.com Page | 13 Development of an Advanced Technique for Historical Document Preservation Latika Kumawat 1 , Navneet Agrawal 2 1 M.Tech Scholar, Department of ECE, CTAE College, Udaipur, Rajasthan, INDIA 2 Assistant Professor, Department of ECE, CTAE College, Udaipur, Rajasthan, INDIA Abstract—In this paper, technique used for historical document preservation is explored. In this paper a noise estimation technique is applied to know noise standard deviation. We first estimate or detect level of noise present in noisy images by selecting weak textured patches in image on the basis of gradient matrix and its statistical properties, then eliminate that noise through non local means(NLM) denoising technique that will use estimated noise level as filtering parameter for eliminating noise from the image. This technique is based on weighted average of the similar pixels in historical image. Non local means techniques removes noise from images without taking care of noise level ,it is mandatory to take care of noise level for best preserving Historical document images. Keywords— Filter, Historical document, Noise, Noise removal method, Noise level estimation. I. INTRODUCTION Historical documents play a very important role as it expresses the difference between past and present as well as future too.So it is important to retrieve the information in order to preserve the Historical document images.There are many factors which affect the accuracy of text documents. When historical documents are digitized by Scanning of the documents, they generally contain noise due to use of scanner , printer and age of the document. Historical documents are different from the other documents in terms of foreground and background,so they are to be treated in different ways.[4] The noise estimation and the noise removal technique [1]proved itself much better as a important part in enhancing or to make historical documents readable.This paper has been organized in number of sections. Section 2 involves basic steps used. In section 3 noise level estimation is explained. Section 4 having the details of noise removal technique .Section 5 deals with the output of the used techniques. and section 6 comprises of conclusion. II. STEPS INVOLVED Steps involved in the preservation of Historical document preservation are as follows in fig 1: Fig 1: Block diagram of the steps involved in preservation It is very complicated to get useful information from noisy images. That is why it is necessary to denoise images to get useful information from them. But performance of denoising techniques or degree of removal of noise from noisy images usually depends on the level of noise present in images. So it is an important task to know about the true level of noise present in images and then depending on that standard deviation of noise, noise can be removed from images by using specific image denoising techniques. III. NOISE LEVEL ESTIMATION In order to remove noise we must know the level of the noise present in the scanned historical document. Estimation or detection of the noise level for image is very important parameter to improve the effectiveness of the denoising. A patch based noise level estimation algorithm[6] is proposed in the current work, with patches generated