Study on circular double phase only function rotation multiplexing for optical image encryption

• Main Authors: XU, YOT-WEI, 許祐維
• Other Authors: Chang, Hsuan-Ting
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/ebrgpq

碩士 === 國立雲林科技大學 === 電機工程系 === 107 === In this paper, an optical encryption system based on circular double-phase rotation multiplexing in Fresnel transformation is proposed. The optical architecture we use is modified Gerchberg-Saxton algorithm and double random phase retrieval algorithm. We propose four optical image multiplex encryption methods. The first is to use a modified GS algorithm. We add a circular double phase structure, calculate the second phase function, and use the second phase function to rotate the angle to affect the reconstruction. affect the reconstruction of image quality, the second is the same as the first method, using the circular double-phase modified GS algorithm to calculate the first phase function, using the first phase function angle rotation, affect the reconstruction of image quality, the third is based on double random phase capture algorithm calculates two phases, and adds a rotation angle to the second phase, before phase modulation and after phase synthesis. Using these two rotation angles, affect the reconstructs of image quality, and the fourth is the same as the third. The method uses a double random phase retrieval algorithm to calculate two phase functions, and when two phase functions are calculated, a rotation angle is added to each of the two phase functions, and the two rotated phase functions are used to affect the reconstructed of image quality, compared to the previous multiplexed image encryption using the Fresnel conversion wavelength, position and imaging plane tilt angle parameters , When the image is decrypted, it is necessary to know the correct phase angle or rotated synthesis phase angle parameter mask, before the target image correctly decrypted, therefore high safety on encryption.