Research On Single Pixel Imaging And Encryption Technology Based On Orthogonal Modulation

Computational ghost imaging,as a novel single pixel imaging(SPI)technology,has great potential and bright prospects in the field of optical information security due to its data compression and encryption performance of real-valued ciphertext.However,encryption techniques based on computational ghost imaging also have shortcomings such as serious noise in decryption results,large numbers of keys,and unsatisfactory imaging results for complex amplitude images.To address these issues,this article proposes the following SPI based imaging and encryption scheme.(1)An image encryption technique is proposed based on random orthogonal modulation for single pixel imaging and biometric encryption.Firstly,the method uses a computer to generate two sets of random integer sequences as keys,respectively scrambling the rows and columns of the Hadamard matrix;Then,a digital micromirror device is used to project the orthogonal matrix obtained by the scrambling method as a modulation template onto the target image for single pixel imaging,and a bucket detector is used to obtain the ciphertext;Finally,the encryption process is completed by performing fingerprint encryption on two sets of random integer sequences and ciphertext.The decryption of secret images is the inverse process of encryption.Experiments and simulations show that this method can effectively resist certain plaintext attacks from attackers,and has good robustness.Even when subjected to common noise interference such as Gaussian noise,the decrypted image can still restore the original image information.(2)A single pixel complex amplitude imaging and encryption method based on random orthogonal modulation is proposed.This method first generates two sets of random sequences(as encryption keys)by computer to scramble the rows and columns of the generated orthogonal complex matrix to obtain a random orthogonal complex matrix,and then modulates them into the desired modulation template by using two pure phase masks to interfere,projecting them onto the target image,The optical signal reflected or scattered by the target image is combined with another reference optical signal modulated by an acoustooptic modulator to form a heterodyne frequency signal,which is eventually collected by a photodetector;Then,the photodetector detection results are used to obtain the amplitude and phase information of the target image through heterodyne frequency filtering and multiplexing detection methods;Finally,the amplitude and phase information obtained each time is arranged into a complex form and the target image is reconstructed using inverse matrix transformation.Simulation experiments show that this method can achieve rapid imaging of complex amplitude objects.When subjected to some common noise attacks(such as Gaussian noise),the reconstructed complex amplitude image can still recognize the original information,with good robustness.Moreover,it uses a random sequence as a key,achieving encryption of the target image,and enhancing system security.