高度自动化获取书籍扫描图像畸变参数的理论

提出一种利用打印直线获取书籍扫描图像畸变校正所用参数的新方法,可提高畸变参数获取的自动化程度。对于打印在纸张上的直线,当打印纸夹在书籍中扫描图像时,打印纸随着书籍页面弯曲成曲面,它也随之弯曲成空间曲线,其扫描图像则为平面曲线,包含了页面弯曲状态的信息。理论上分析了该平面曲线与畸变参数之间的关系。利用这种关系及最小二乘法原理,对该平面曲线上的点进行曲线拟合,可自动计算出对应页面的畸变参数,不再像以前那样必须进行人工调整。

Theory of high automatic determination of distortion parameters for scanned book image

A new method is presented that make use of printed straight line to determine the distortion parameters for correcting the distortion of scanned book image, which can be used to improve the automation degree of distortion parameters determination.When a paper with printed straight line is put into a book to scan images,the paper is twisted into curved surface as the scanned page,and the printed straight line is twisted into space curve line.The scanned image of the space curve line is a plane curve line,it contains distortion information of the twisted page.Relation between the coordinate of every point on the plane curve line and the distortion parameters of the twisted paper is deduced.This relation can be used along with the least-square method to do curve fitting,thus determine the distortion parameters of that page automatically,without any manual operation which is necessary in former methods.