Design Of The Phase-only Optical Anti-counterfeiting Mask Based On The Parallel Optimization Algorithm

The rapid development of information technology has brought convenience to people's lives,but also bring a lot of security risks to individuals and society.Especially in recent years associated with high-tech ID cards,driver's license,credit cards,bills and other large counterfeit fraud cases increased year by year,resulting in significant economic losses to the state and individuals,and serious adverse effects.Therefore,it has become one of the important research topics in the field of information security to improve the security capability of all kinds of important documents,and to seek new and more secure and reliable security technology.Pure phase optical anti fake mask is a kind of transparent diffractive optical element,which encodes information can not be perceived by conventional intensity detectors,and difficult to replicate,with good security features.This paper is based on an in-depth study two classic anti-counterfeiting mask design method of the Gerchberg-Saxton(GS)algorithm and constraint set Projection Onto Constraint Set(POCS),combined Stochastic Parallel Gradient Descend(SPGD)algorithm with GS and POCS algorithm,take advantages of each algorithm,proposed improved phase anti fake mask film design method,through analysis and simulation,the improved algorithm can effectively improve the quality of reconstructed picture decoding.This paper mainly completes the following several aspects of work:(1)Around the classic phase retrieval algorithm of the GS algorithm,POCS algorithm,the phase only optical anti-counterfeiting mask making process and design methods are analyzed and discussed in detail to verify the every kind of algorithm performance in image quality restoration and further improved algorithm proposed provides a theoretical basis.(2)The Stochastic Parallel Gradient Descent(SPGD)algorithm is introduced an optical security mask design,which are combined the traditional phase recovery GS algorithms with SPGD algorithm,proposed SPGD-GS algorithm,SPGD-POCS algorithm,by analysis and simulation,proved that the improved security pure optical phase mask design method effectively improve the quality of the decoded image recovery,and with the increase in the number of phase quantization step,the effect is even more obvious.(3)The SPGD algorithm were concurrent design,respectively combined the GS algorithm with the POCS algorithm,proposed CSPGD-GS algorithm and CSPGD-POCS algorithm.Computer simulation results show that,the improved method can further improve the restoration of optical anti-counterfeiting mask of the decoded image quality.