基于数字全息与随机组合的无串扰图像加密与水印研究

Cross-Talk Free Image Encryption and Watermarking by Digital Holography and Random Composition

在传统的图像水印方法中,通常直接添加编码到宿主图像和水印图像,因此,这两幅图像在解密的过程中会存在串扰。为了消除这种影响,提出了一种基于数字全息技术的新方法,将两幅隐藏图像产生的两幅全息图的所有图像像素重新排列,并用随机散射矩阵(RSM)将其组合成一组复合全息图;在解密过程中,利用RSM可以确保每个全息图像的精确恢复,从而实现每幅图像无串扰噪声的完美重建,利用相移干涉和双随机相位编码技术进行计算机仿真,验证该方法的可行性及其对遮挡和附加噪声的鲁棒性。该方法适用于二维和三维图像,附加的RSM还可以作为一种密钥提供更高的安全级别。

In previous image watermarking methods,an encoded host image and a watermark image are usually directly added.Therefore,the two images have cross-talk in the decryption step.In order to eliminate this effect,a new method based on digital holography interferometry is proposed,in which all the image pixels of the two sets of holograms resulted from two hidden images are rearranged and integrated into one set of composite holograms with a random scattering matrix（RSM）.In decryption the use of this matrix can ensure the exact retrieval of each hologram,and then the perfect reconstruction of each image without cross-talk noise can be achieved.In the decryption process,the use of RSM can ensure the accurate recovery of each holographic image,so as to achieve a perfect reconstruction of no crosstalk noise in each image.The computer simulation is performed using phase-shift interference and double random phase encoding techniques to verify the feasibility of the method,its robustness to occlusion and additional noise.this method is suitable for 2D and 3D images,and the additional RSM can also provide a higher level of security as a key.