A zero-watermark algorithm for multiple images based on visual cryptography and image fusion

At present, it is difficult for the multiple images zero-watermark algorithm to protect all the images in the image set, and repeated operations will reduce the efficiency of the algorithm. To solve these issues, the proposed algorithm can design a reasonable copyright protection scheme according to the number of images in the image set to realize the protection of all images, and reduce the cost of time and storage. The gray-weighted average image fusion method is used to fuse multiple normalized standard images into one image. The LWT(Lifting the Wavelet Transform)-QR decomposition is applied to the effective area of the fusion image to obtain the robust feature image. Non-extended visual cryptography is used to enhance the security of the algorithm. A zero-watermark image is obtained by using the XOR manipulation for the feature image and the public shared image. Experimental results demonstrate that the proposed algorithm has good performance.