Study On Quantum Image Scrambling And Watermarking

As a new research direction in the quantum computing,quantum image processing(QIP)has recently received more and more extensive attention.From the original quantum image representation models,geometry transformation,image segmentation and feature extraction to the quantum image scrambling,watermarking and encryption,etc.,All of these show the great development of QIP.However,it is not enough to be a complete system,which requires further research and perfection.Based on the study of QIP,this paper carries out works about the following two aspects:1,In order to expand the study of quantum image scrambling technology,to design faster and better quantum image scrambling algorithm,this paper firstly proposes two kinds of scrambling schemes for quantum gray image according to the characteristic of image bit-plane: the basic bit-plane scrambling and improved bit-plane scrambling,both of them belong to color space scrambling.Then,to increase the security,two new scrambling methods on the basis of the improved scrambling combined with simple position transformation are presented: with position rotation and with gray-code transformation on position.The above four methods each with advantages,but they all work obviously,not only can they destroy the histogram distribution of the image,but also their complexity is very low and is far superior to the corresponding classical algorithm.Although,these methods designed for quantum gray image,they can extend to color image.2,To solve the problem of watermark embedding and extracting of quantum color images,a watermarking scheme to embedding the quantum binary image into a quantum color image is first proposed.For the embedding procedure,the least significant bits of the color carrier image are replaced by the color of the watermark.Before embedding,the watermarking could obtain a scrambling to enhance the security;In the extracting procedure,the solution to determine the color of the extracted watermark is heading toward majority rule so that the robustness of watermarking is improved.Next this paper designs the methods convert quantum gray image and quantum color image into quantum binary image.Therefore,the watermarking embed problem with the gray image and color image as watermark can be transformed into the solved problem that binary image as watermark.The simulation result show that the watermarking scheme has good invisibility and has advantage in robustness performance compared with existing scheme.