Wavelet transform for skew angle detection in printed Persian documents
When a document is fed to a scanner for digitization, it suffers from some degrees of skew. This skew has a detrimental effect on character recognition. In this paper we present two novel skew estimation methods for scanned Persian documents that estimates skew angles based on the wavelet decompositions and projection profile analysis. In the first algorithm, one row of the skewed document images is selected and is decomposed by the wavelet transform and in the second algorithm the whole document image is decomposed. Then, in both algorithms the matrix containing the absolute values of the horizontal subband coefficients, is then rotated through a range of angles. A projection profile is computed at each angle, and the angle that maximizes the maximum projection profile is regarded as the skew angle. The first algorithm is used for limited angle but second algorithm is used for wide angles.
Document analysis Skew detection and correction Wavelet transform Projection profile
Samira Nasrollahi Dizajyekan Afshin Ebrahimi
Department of Electrical Engineering, Sahand University of Technology, Tabriz, Iran
国际会议
Third International Conference on Digital Image Processing(ICDIP 2011)(第三届数字图像处理国际会议)
成都
英文
243-247
2011-04-15（万方平台首次上网日期，不代表论文的发表时间）