A novel approach for blind source separation of mixed document images in Farsi scanned documents

In the field of mixed scanned documents separation, various studies have been carried out to reduce one (or more) unwanted artifacts from the document. Most of the approaches are based on comparison of the front and back sides of the documents. In some cases, it has been suggested to analyze the colored images, however, because of the calculation complexity of the approaches, they are not very applicable in practical applications. Furthermore none of them are tested on Farsi documents. In this paper, an applicable approach to large size images is presented which is based on image block segmentation (mosaicing). The advantages of this approach are less memory usage, combining of simultaneous and ordinal blind source separation methods in order to increase their efficiency, reducing calculation complexity of the algorithm into twenty percents of the basic algorithm, and high stability in noisy images. In noiseless conditions, the average signal to noise ratio of the output images is obtained 29.25 db. Furthermore, all of these cases have been tested on Farsi official documents. By applying the suggested ideas, considerable accuracy is achieved in the results, at minimum time. In addition, various parameters of the proposed algorithm (e.g. the size of each block, appropriate initial point, and number of iterations) were optimized.