Restoration of motion blurred document images

Abstract

Motion blur often decreases the quality of document image and makes the text information within the document images unreachable by optical character recognition (OCR) or by a person. This paper presents a blur correction technique that aims to correct motion blur within document images. Given a blurred document image, an alpha channel map is first constructed based on specific image characteristics that are associated with text documents. Several blur parameters including blur direction and blur extent are then estimated from the constructed alpha channel map. Finally the blurred document image is restored by using Richardson-Lucy deconvolution technique based on the estimated blur parameters. Experiments on a number of document images with motion blur show that the proposed technique improves the document visual quality as well as the OCR performance significantly. © 2012 ACM.