渗透性检材上潜在指印检测技术研究
文献类型：学位论文
| 作者 | 赵成 |
| 文献子类 | 硕士 |
| 导师 | 黄立华 |
| 关键词 | 指印检测 Fingerprint Detection 潜在指印 Latent Fingerprint 渗透性纸张 Porous Paper 紫外激光诱导荧光 UV Induced Fluorescence 二维激光扫描系统 Two-Dimensional Laser Scanning System |
| 其他题名 | Research of Latent Fingerprint Detection Technology on Porous Materials |
| 英文摘要 | 指纹因其“生来具有、人各不同、终身不变、触物留痕”的特性成为如今身份验证的首要证据，被广泛运用于众多领域，特别是刑事案件侦查领域。潜在指印是罪犯在犯罪现场最常遗留的一类指印，这类指印在自然光下无法通过肉眼直接观察到，如果不能采取有效的措施将其显现或增强成清晰可见的指印，则指纹的获取、分析和鉴定等后续工作将难以开展。经过一百多年的探索、研究和实践，潜在指印检测技术仍然是世界各国研究的热点，存在一些亟待解决的问题，例如某些显现试剂存在毒性、预处理容易损坏指印原件和渗透性检材上显现效果不佳等。 基于潜在指印残留物中有机物成分在紫外光激发下会产生荧光的特性，开展了渗透性检材上潜在指印检测技术研究，主要内容如下： (1)对国内外潜在指印检测技术的发展现状进行了总结，并分析了现有的检测技术的优缺点，最后针对现有检测技术中存在的不足，提出了本文的研究目的和研究意义。 (2)搭建了一套指印荧光光谱测量装置，获得了266 nm紫外光激发下潜在指印荧光光谱和具有较强背景荧光的渗透性纸张上潜在指印的荧光光谱。基于潜在指印残留物中有机物成分在紫外光激发下会产生荧光的特性，开展了渗透性检材上潜在指印检测技术研究，并搭建了一套潜在指印检测装置。该装置采用266 nm紫外激光器作为激发光源，通过二维激光扫描系统对潜在指印区域进行快速扫描，采用窄带滤光片滤除干扰光，采用剔除奇异亮点和提高对比度的方法复原指印荧光图像。同时，分析了装置中各个组成模块需要达到的技术指标，并根据这些技术指标开展了关键器件的选型。 (3)采用LabVIEW与MATLAB设计了潜在指印检测程序，主要包括三维电动平台控制模块、二维扫描振镜控制模块、数据同步采集与存储模块以及数据处理模块，实现了潜在指印检测装置的控制和潜在指印荧光信号的处理。 (4)使用潜在指印检测装置对五种渗透性纸张上的汗指印和油指印分别开展了实验研究。以指印条纹对比度为依据优化实验参数，获得了高对比度的潜在指印图像。同时，对这五种纸张上放置不同天数的陈旧潜在指印开展了实验，并对指印图像的指印条纹对比度进行了分析，发现随着放置天数的增加，指印条纹对比度逐渐减小，这可能是由于随着时间的推移，潜在指印残留物中的角鲨烯、油酸、棕榈油酸等不饱和化合物开始逐渐消失的原因。 (5)对全文工作进行了总结，列出了主要创新点，同时指出了下一步需要开展的研究工作。; Fingerprints have become the primary evidence of today's identity verification because of the characteristics of being “born with people, vary from people to people, unchanged in life, leaving traces when touch”. Fingerprints are widely used in many fields, especially in the field of criminal case investigation. Latent fingerprints are the most commonly encountered type at crime scenes and cannot be directly observed by the naked eye under natural light. If effective measures cannot be taken to show latent fingerprints or strengthen them to become clear visible fingerprints, it will be difficult to carry out subsequent works such as fingerprint acquisition, analysis and identification. After more than 100 years of exploration, research and practice, latent fingerprint detection technology is still a research hotspot all over the world. There are still some problems need to be solved, such as some reagents are poisonous, pretreatments are easy to damage fingerprints, and bad detection effect on porous materials, etc. Based on the characteristic that the organic components of latent fingerprints will produce the fluorescence when induced by ultraviolet, this paper carried out the research on the detection of latent fingerprints on the porous materials. The main contents are as follows: (1)Summarized the development status of latent fingerprint detection technologies at home and abroad, and analyzed the advantages and disadvantages of existing detection technologies. Finally, proposed the research purpose and significance of this paper in view of the shortcomings in existing detection technologies. (2)Set up a fingerprint fluorescence spectrum measurement device, and obtained latent fingerprint fluorescence spectrum and latent fingerprint fluorescence spectrum on the porous paper with strong background fluorescence under the excitation of 266 nm ultraviolet light. Based on the characteristic that the organic components of latent fingerprints will produce the fluorescence when induced by ultraviolet, carried out the research on the detection of latent fingerprints on the porous materials, and set up a latent fingerprint detection device. The device used a 266 nm ultraviolet laser as excitation light source, adopted a two-dimensional laser scanning system to rapidly scan the latent fingerprints, filtered interference light by narrow band filter, optimized the experimental parameters according to fingerprint striae contrast, and the latent fingerprint fluorescence images were reconstructed by removing the singular highlights and enhancing fingerprint striae contrast. At the same time, analyzed the technical indexes required by each component module in the device, and selected the best key components according to these technical indexes. (3)Designed the latent fingerprint detection programs by LabVIEW and MATLAB. The programs mainly included three-dimensional electric platform control module, two-demensional scanning galvanometer control module, data synchronization acquisition and storage module and data processing module, which achieved the control of the latent fingerprint detection device and the processing of latent fingerprint fluorescent signals. (4)Carried out experimental study of sweat fingerprints and sebaceous fingerprints left on five kinds of porous paper by the latent fingerprint detection device. By optimizing experimental parameters according to fingerprint striae contrast, high-contrast latent fingerprint images were obtained. At the same time, carried out the experiments of aged latent fingerprints with different days on these five kinds of paper, and analyzed fingerprint striae contrast of detection results. The experimental results showed that as the number of days increased, the fingerprint striae contrast gradually decreased, which may be due to the gradual disappearance of unsaturated compounds such as squalene, oleic acid, and palmitoleic acid in latent fingerprint residues over time. (5)Summarized the main works of this paper, listed the main innovation points, pointed out the research works which need to be done in the next step. |
| 学科主题 | 光学工程 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/31098]  |
| 专题 | 中国科学院上海光学精密机械研究所 |
| 作者单位 | 中国科学院上海光学精密机械研究所 |
| 推荐引用方式 GB/T 7714 | 赵成. 渗透性检材上潜在指印检测技术研究[D]. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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