Speckle-suppressed optical implementation for JTC-based image cryptosystem

Speckle noise results in a serious quality degradation in reconstructed image of the optical implementation for image cryptosystem using a joint transform correlation (JTC) architecture. In this paper, a speckle-suppressed optical implementation for JTC-based image cryptosystem is proposed. The encryption process is performed optically, while the decryption process is performed digitally. In this paper, the distribution of objects in the input plane is optimized on basis of analysis for the inherent noise of cryptosystem, such as dark current noise of the CCD camera. Consequently, speckle noise in the reconstructed image is effectively decreased. Furthermore, less times of record are required, and there is no increase in hardware and complexity. Simulations and experimental results demonstrate the validity and effectiveness of the proposed speckle-suppressed scheme.