An Efficient Algorithm for Automatic Skew-Correction of Color Document Image
彩色文档图像的倾斜自动校正算法

The automatic skew-correction of scanned color document image is a necessary step undergone before some processing such as OCR(optical character recognition).For the purpose of accurate and efficient automatic correction,two algorithms,namely skew-detection and skew-adjustment,are proposed.The skew-detection algorithm,which is based on the analysis of texture complexity of document image with homogeneous background,solves the problem of how the accurate skew angle can be found.Besides the rotation transform,the skew-adjustment algorithm includes a dual linear interpolation algorithm for color compensation based on linear dependence among the colors in the neighborhood to accomplish the skew-correction of a color image and the elimination of the "Saw tooth" phenomenon resulted from the integer-operation during the coordinates transformation.In the end,the authors illustrate their experimental results,which show that the presented algorithm is exact,efficient,and practical for color documents whose background are not complex.