用于墙地砖缺陷检测的自动精确图像配准方法

将规则图案墙地砖的精确配准方法用于墙地砖表面缺陷检测，通过对图像进行预处理及边缘检测，找出墙地砖的四条边及左上角，首先对参考砖和待测砖之间的位移和旋转角度进行初步估计，对待测墙地砖进行平移，使其左上角与参考墙地砖的左上角对准并旋转完成初步配准，然后，用互相关法寻找更精确的平移参数进行精确配准，这样可以在像素与像素之间进行直接比较以进行缺陷检测，实验结果证明该方法能有效检测出像孔穴、裂纹等一般缺陷。

Precise Automatic Image Registration Method of the Defect Detection for Ceramic Tiles

A precise automatic registration method of the defect detection for ceramic tiles with deterministic patterns was investigated. The four edges and the left-above corner of the tile were located by the preprocessing and edge detection of the image. Firstly, the displacement and rotation angle between the reference tile and the tile to be inspected were primarily estimated. Then shift and rotate the tile to be inspected in order to make its left-above corner aim at that of the reference tile, thus completing a primary registration. Secondly, more precise displacement parameters were obtained by the cross-correlation method and were then utilized to make a precise registration, thus carrying out the defect detection directly between the pixels. Experimental results indicate that the proposed method can be effectively used to detect common defects such as holes and cracks.