Abstract:  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 detec-tion 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 ob-tained 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．

Key words: image registration, ceramic tile, defect detection, cross-correlation method