ANALYSIS OF DECOLORIZATION METHODS AND ITS APPLICATION

Abstract

Contrast Preserving Decolorization is rgb-to-gray conversion of a color image, which tries to preserve the contrast in a Gray-scale image, as it was in the original color image. In this dissertation, various contrast preserving decolorization techniques such as SPDecolor and CPrgb2gray have been analysed and they have been applied in the field of binarization of historical documents. Pre-processing is an essential step in the binarization of historical documents in order to preserve its information content, especially in the case of low contrast images. This work addresses the problem of contrast preservation of the historical documents using contrast preserving decolorization based binarization process. For certain types of degradation such as faded/faint text , the proposed SPDecolor based pre-processing technique may perform better for local binarization techniques over the global binarization techniques. This dissertation also compares various local binarization algorithms using both conventional and contrast preserving pre-processed techniques. Improved experimental results are obtained on the DIBCO(2009-11) dataset for proposed SPDecolor based framework against CPrgb2gray and conventional color-to-gray binarization methods.