Document skew detection based on hough space derivatives

One of the basic challenges in page layout analysis of scanned document images is the estimation of the document skew. Precise skew correction is particularly important when the document is to be passed to an optical character recognition system. In this paper, we propose a very generic and robust method which can cope with a wide variety of document types and writing systems. It uses derivatives in the Hough space to identify directions with sudden changes in their projection profiles. We show that this criterion is useful to identify the horizontal and vertical direction with respect to the document. We test our method on the DISEC´13 data set for document skew detection. Our results are comparable to the best systems in the literature.