a method based on the technique of image registration is proposed for detecting the appearance defects of Super-twisted Nematic Liquid Crystal Display (STN-LCD). The standard template LCD image is first recovered from possible non-uniform illumination, and then the statistical information of each region is collected by image thresholding and region labeling. The template and testing image are registered by control-point detection and affine transform. The defects including stroke-loss and pinhole of the LCD can then be detected by using region statistics such as mean and standard deviation of grayscales. To improve the accuracy of image registration, a special scheme of control-point selection and hybrid image interpolation is proposed. Experimental results show that the proposed method is robust and accurate, and can detect STN-LCD defects automatically. The proposed method is used for industrial applications, and offers advantages over the traditional manual inspection manner.