一种新的变形石刻图像校正算法

A new distortion rectification algorithm for carved stone images

针对大幅摩崖石刻拍摄时因地势限制等原因导致不能从正面采集石刻图像而影响数字化石刻拓片制作,提出一种基于石刻特征的变形图像校正算法。利用二维Otsu自适应分割算法将图像分成背景和前景2部分,根据石刻中四边形或汉字的笔画、结构特征找出4个标记点,由标记点的位置求解双线性空间变换方程,通过双线性插值方法实现变形图像校正。实验结果表明,该算法对因拍摄角度受限造成的石刻图像变形能取得良好的校正效果。

When taking cliff carving images with camera,image distortion occurs because of the limitation of terrain.To solve this problem,a new distortion rectification algorithm based on carved stone features is proposed.The input image is seg-mented into foreground region and background region using a two-dimensional Otsu adaptive segmentation algorithm.Four labeling points are found out by utilizing quadrangle the structure feature of Chinese characters and the bilinear spatial trans-formation equations are solved.Finally the color in the rectified image is computed through the bilinear interpolation.Exper-imental results show that the algorithm can improve cliff carving image distortion caused by shooting angle.