Research on the halftone image correction algorithm based on cluster analysis

In the extraction of halftone anti-counterfeiting information, the image maybe skew, which causes the anti-counterfeiting information cannot be extracted. Using dots characters to construct the synchronous information, we propose a halftone dots detection algorithm based on cluster analysis. This algorithm detects dots with different in the halftone images, then extract the synchronous information to correct skew image. Experimental results show that this algorithm can effectively detect dots which contain the synchronous information and improve the speed in a degree, which can correct skew images to extract the hidden information.