Color Image Encryption System and Encryption and Decryption Method Based on Compression Holography

Abstract

The invention relates to a color image encryption system and an encryption and decryption method based on compression holography and belongs to the technical field of optical image encryption. The system comprises a laser device, a first reflecting mirror, a second reflecting mirror, a beam expanding and collimating system, a beam splitter, a first spatial light modulator, a second spatial light modulator, a third spatial light modulator, a fourth spatial light modulator, a first random phase mask, a second random phase mask, a third random phase mask, a high-speed image collecting device and a computer. Firstly, gray level images of three channels of color images are extracted and are arranged at the positions with different distances to a CCD to serve as object information needing to be encrypted, the three random phase masks are tightly attached to the three gray level images and then are used for modulating light beams containing the object information, the three light beams are interfered by a beam combining prism and reference light to generate a holographic image, and the gray level images of the three channels are simultaneously encrypted on the same holographic image. Lastly, decryption is carried out with a TwIST algorithm, and color image composition is carried out. According to the color image encryption system and the encryption and decryption method based on the compression holography, the color images can be encrypted through one-time exposure, and the encryption efficiency and the confidentiality degree of the encrypted information are improved.

Description

technical field [0001] The invention relates to an optical image encryption technology, in particular to a compression holography-based color image encryption system and an encryption and decryption method. Background technique [0002] With the construction of the information highway and the development of computer science and technology, the importance of ensuring information security in the process of pursuing the rapid transmission of information has gradually become prominent. Due to the parallelism and rapidity of optical information processing and the advantages of providing multiple encryption dimensions, the use of optical methods to encrypt images has always been an important research aspect of image encryption technology. [0003] Since Philippe Refregier and Bahram Javidi proposed to use double random phase plates to encrypt images, optical image encryption technology has received widespread attention and rapid development. However, due to the difficulty in obta...

AI Technical Summary

Problems solved by technology

This problem will greatly limit the encryption efficiency of color pictures

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