Blind bleed-through removal in color ancient manuscripts

Archaic manuscripts are an important part of ancient civilization. Unfortunately, such documents are often affected by various age related degradations, which impinge their legibility and information contents, and destroy their original look. In general, these documents are composed of three layers of information: foreground text, background, and unwanted degradation in the form of patterns interfering with the main text. In this work, we are presenting a color space based image segmentation technique to separate and remove the bleed-through degradation in digital ancient manuscripts. The main theme is to improve their readability and restore their original aesthetic look. For each pixel, a feature vector is created using color spectral and spatial location information. A pixel based segmentation method using Gaussian Mixture Model (GMM) is employed, assuming that each feature vector corresponds to a Gaussian distribution. Based on this assumption, each pixel is supposed to be drawn from a mixture of Gaussian distribution, with unknown parameters. The Expectation-Maximization (EM) approach is then used to estimate the unknown GMM parameters. The appropriate class label for each pixel is then estimated using posterior probability and GMM parameters. Unlike other binarization based document restoration method where the focus is on text extraction, we are more interested in restoring the aesthetically pleasing look of the ancient documents.The experimental results validate the usefulness of proposed method in terms of successful bleed-through identification and removal, while preserving foreground-text and background information.