A Binarization Technique for Extraction of Devanagari Text from Camera Based Images

Abstract

This paper presents a binarization method for camera based natural scene (NS) images based on edge analysis and morphological dilation. Image is converted to grey scale image and edge detection is carried out using canny edge detection. The edge image is dilated using morphological dilation and analyzed to remove edges corresponding to non-text regions. The image is binarized using mean and standard deviation of edge pixels. Post processing of resulting images is done to fill gaps and to smooth text strokes. The algorithm is tested on a variety of NS images captured using a digital camera under variable resolutions, lightening conditions having text of different fonts, styles and backgrounds. The results are compared with other standard techniques. The method is fast and works well for camera based natural scene images.