We propose a new method to add different images together by optical implementation that is realized by the multi-exposure based on fractional Fourier transform hologram. Partial image fusion is proposed and realized b...We propose a new method to add different images together by optical implementation that is realized by the multi-exposure based on fractional Fourier transform hologram. Partial image fusion is proposed and realized by this method. Multiple images encryption can also be implemented by the multi-exposure of the hologram based on fractional Fourier transform. Computer simulations prove that this method is valid.展开更多
We analyse the diffraction result of optical field after Cosine zone plate, and theoretically deduce its transform matrix. Under some conditions, its diffraction distribution is a mixture of fractional Fourier spectra...We analyse the diffraction result of optical field after Cosine zone plate, and theoretically deduce its transform matrix. Under some conditions, its diffraction distribution is a mixture of fractional Fourier spectra. Then we use Cosine zone plate and its diffraction result to image encryption. Possible optical image encryption and decryption implementations are proposed, and some numerical simulation results are also provided.展开更多
We propose a novel method for image encryption,which is realized by the Collins formula with the random shifting method.The Collins formula can denote different optical transforms by one expression with different ABCD...We propose a novel method for image encryption,which is realized by the Collins formula with the random shifting method.The Collins formula can denote different optical transforms by one expression with different ABCD elements.For a generalized optical system,the ABCD elements can be randomly chosen,so the keys are increased and the security of the system is strengthened.Finally,some computer simulations are given for different encryption systems to prove the possibilities.The encryption effect is good,and people without the correct keys can not obtain the information easily.展开更多
基金Supported jointly by the National Natural Science Foundation of China and the China Academy of Engineering Physics under Grant No 10276034.
文摘We propose a new method to add different images together by optical implementation that is realized by the multi-exposure based on fractional Fourier transform hologram. Partial image fusion is proposed and realized by this method. Multiple images encryption can also be implemented by the multi-exposure of the hologram based on fractional Fourier transform. Computer simulations prove that this method is valid.
文摘We analyse the diffraction result of optical field after Cosine zone plate, and theoretically deduce its transform matrix. Under some conditions, its diffraction distribution is a mixture of fractional Fourier spectra. Then we use Cosine zone plate and its diffraction result to image encryption. Possible optical image encryption and decryption implementations are proposed, and some numerical simulation results are also provided.
基金the National Natural Science Foundation of China under Grant No 11147138the Natural Science Foundation Zhejiang Province under Grant Nos LQ12A04001 and R1090168the Natural Science Foundation of Educational Department of Zhejiang Province under Grant No Y200908864.
文摘We propose a novel method for image encryption,which is realized by the Collins formula with the random shifting method.The Collins formula can denote different optical transforms by one expression with different ABCD elements.For a generalized optical system,the ABCD elements can be randomly chosen,so the keys are increased and the security of the system is strengthened.Finally,some computer simulations are given for different encryption systems to prove the possibilities.The encryption effect is good,and people without the correct keys can not obtain the information easily.
