Robust pre-processing techniques for OCR applications on mobile devices

Abstract

Text detection and recognition in natural images using a single mobile device is becoming relevant due to the increasing interest in Optical Character Recognition (OCR) applications. OCR application on mobile devices is no longer a dream due to the advancement in mobile technology. There are many ongoing researches in this field. Most of the researches focus on the OCR engine of the application and there is not much focus on the processing stage of the OCR application. Pre-processing plays a major role in optimizing the image for character recognition. Thus, in this paper, two pre-processing techniques are proposed for the mobile OCR application. The first technique helps to locate a sign in a natural image efficiently, while the second technique implements Otsu's threshold algorithm to convert images into binary image. These techniques are implemented in an OCR mobile application which is developed using desktop open sources library. After implementation, the OCR application is tested with 50 sign images to verify the accuracy. Experimental results have demonstrated that these techniques can significantly improve the OCR accuracy and decrease the overall computation time. Copyright © 2009 ACM.