This paper describes the secure storage and matching of latent fingerprints using phase shifting digital holography. A phase shifting digital holographic system is proposed for imaging of latent fingerprints, which can be applied in the criminal investigation field. Digital holography is one of the accurate and fast technique for measuring 3D information, by acquiring both amplitude and phase information from the object. Digital holography uses a Charge-Coupled Device (CCD) to record the interference pattern. In digital holography, the reconstructed image unavoidably contains the conjugate image and the zeroth order beam, resulting in low resolution. This problem can be overcomed by using phase shifting digital holography. Phase shifting digital holography is a technique by which multiple holograms are taken corresponding to the various phase differences between the object beam and the reference beam. One of the most secure storage methods is digital holographic data storage which provides a credible way in the fingerprint acquisition in the criminal investigation field. The phase shifting digital holograms of the latent fingerprint are acquired and then numerically reconstructed. The reconstructed fingerprint is then compared with the database after further processing to find whether it is a match or no match. The investigations have been conducted through experiments and computer simulations. The parameters used for analyzing the performance of the system are False Matching Rate (FMR), False Non-Matching Rate (FNMR) etc. This system shows a remarkable performance improvement over digital holographic techniques. The method can be explicitly used in forensic applications.

本文介绍了使用相移数字全息技术安全存储和匹配潜在指纹的方法。提出了一种用于潜在指纹成像的相移数字全息系统，可应用于刑事侦查领域。数字全息术是通过从物体获取幅度和相位信息来测量 3D 信息的准确且快速的技术之一。数字全息术使用电荷耦合器件 (CCD) 来记录干涉图样。在数字全息术中，重建的图像不可避免地包含共轭图像和零阶光束，导致分辨率低。这个问题可以通过使用相移数字全息术来克服。相移数字全息术是一种根据物体光束和参考光束之间的各种相位差拍摄多个全息图的技术。最安全的存储方式之一是数字全息数据存储，它为刑事侦查领域的指纹采集提供了一种可靠的方式。获取潜在指纹的相移数字全息图，然后进行数值重建。重建的指纹在进一步处理后与数据库进行比较，以确定它是匹配还是不匹配。调查是通过实验和计算机模拟进行的。用于分析系统性能的参数有误匹配率（FMR）、误不匹配率（FNMR）等。该系统显示出比数字全息技术显着的性能改进。该方法可以明确用于取证应用程序。