A range free skew detection technique for digitized Gurmukhi script documents

In this paper, a range free skew detection technique for machine printed Gurmukhi documents is presented. This approach can easily be extended to other Indian language scripts such as Devnagri and Bakngla. Most characters in these scripts have horizontal lines at the top called headlines. The characters forming a word are joined at the top by headlines, so that the word appears as one single component with a headline. The ratio of pixel density above and below the headline of any word in Gurmukhi script is always less than 1. These inherent characteristics of the script have been employed and a new algorithm based on the projection profile method has been devised. By inspecting horizontal and vertical projections at different angles in range [0°, 90°], the skew angle of the document in range [-180°, 180°] can be determined. Thus this approach is not limited to any range of skew angle and skewness in any document with orientation portrait or landscape and placed at any angle can easily be detected and removed