Effective Image Authentication Algorithm Based on Image Halftone Technique

Based on the image halftone technique, a new effective image authentication algorithm is proposed with self repairing ability. First, the original image is quantized by 4 bit based 011 the error diffusion image halftone, and then the result is permuted by chaos operator, at the same time the halftone color set is constructed with the least quantization error. Next, the permuted image is hidden into the original image based on the error diffusion watermark algorithm. When the watermarked image is received, to verify the authenticity of the received image, the hidden information is extracted out from the received image and permuted inversely. If the received image is similar to the extracted information, the received image is creditable, else that is to say, there exists a local region that is dissimilarity, i.e. the region is tampered, according to corresponding region of extracted information, the tampered region is repaired. Finally, experimental result to demonstrate the effectiveness of the proposed image authentication technique is presented.