颅骨三维模型制作和数据库的构建

目的采用激光扫描深度图像法和CT影像法,制作颅骨模型,并建立无身源颅骨模型数据库。方法收集各省(区)送检的59例无身源颅骨样本,采用三维激光扫描仪进行颅骨深度图像的采集;采用多排螺旋CT进行颅骨断层影像数据的采集。分别经处理后建立颅骨三维模型。利用3D打印技术实现数字颅骨模型的实体复制。建立具有颅骨信息查询和三维模型显示的无身源颅骨模型数据库。结果采用深度图像法可以获得颅骨的外表面模型,且通过调整扫描仪的参数使细节特征更清晰。采用CT断层影像法可以重建颅骨的内、外部结构,且对于牙齿具有更好的重建结果。建立数据库并将59例无身源颅骨样本信息和三维模型纳入数据库。结论三维建模和3D打印技术可实现对颅骨的重建和模型复制。无身源颅骨数据库的构建,可实现存储和管理颅骨样本的各类信息和三维数据,有助于查询和信息共享,对法医学实践有积极的应用价值。     

高精度三维人脸图像数据库

3D人脸图像数据库广泛应用于计算机视觉、动画绘图设计、医学等很多领域。在法庭科学领域,采集三维人脸图像并建立数据库,可进行人像特征分类、统计人像特征的分布以及训练人像模型,这些分析是人像比对和识别的基础。与传统的二维数据库相比,三维(3D)人脸图像库能够提供更多信息,例如,三维人脸图像的空间结构和形状包含多视角轮廓。3D人脸图像采集方法包含多视角几何信息的方法、结构光的方法和3D扫描仪的方法,这些方法有不同的采集设备和环境。国内外已经建立了几个有代表性的3D人脸图像数据库,例如MPI实验室的MPI和BJUT的BJUT-3D,但这些库在分辨率和精度方面尚有不足。本文首先回顾了MPI、BJUT-3D数据库和它们的采集环境,然后对建立中国人的高精度3D人脸图像数据库进行探索研究。用彩色手持三维扫描仪(Artec Spider)采集了1100个3D人脸图像,这些图像包含彩色纹理和深度信息(几何形状和点云),每个人脸图像的几何形状的采样点数目超过2000万,三角面片数目超过4000万。与BJUT-3D人脸数据库在人脸形状、分辨率和纹理等方面的比较结果显示,本研究采集的人脸图像有更高的精度,在嘴巴、鼻子、眼睛等方面比其他数据库中的人脸图像显示了更多的细节。建立的数据库将会支持在3D人像识别和算法评估方面的进一步工作。     

数据仓库技术在消防领域中的应用

目前在公安消防部门使用的软件积累了大量的应用信息和数据，但共享程度低，利用不充分。如何实现信息数据资源的综合开发利用已成为目前制约消防综合信息系统开发建设和发挥效益的瓶颈和难点。数据仓库技术可以将分布在网络中不同系统中的数据集成，为决策者提供有价值的信息。本文详细阐述如何利用数据仓库技术将分散在各消防业务系统中的数据进行集成，为消防部队各项工作提供决策性的信息。[编者按]     

三维激光扫描和计算机技术在交通事故现场还原中的应用

发生道路交通事故后,为尽快疏导交通,交警往往没有足够的时间进行现场勘查,同时交警仍多数使用皮尺测量现场,导致绘制的现场图经常出现数据错误,在事故现场已经被破坏的情况下,根据现场图难以准确还原事故现场。然而,客观、完整地还原事故现场是交通事故成因分析的前提。利用三维激光扫描仪对标记后的现场及事故车辆进行扫描,通过计算机技术对采集的高精度点云数据进行建模后,可准确、高效地还原特定瞬间的事故现场,避免现场图数据错误所造成的影响,为事故现场还原提供一种科学的途径。三维激光扫描仪在道路交通事故司法鉴定事故现场还原中具有明显的优势,尽管存在一定的局限性,但值得推广应用。     

用AUTOCAD创建三维复杂实体模型

本文通过实例将介绍如何在AutoCAD2012中编辑三维对象,利用AutoCAD2012编辑命令,创建出复杂的三维实体模型.     

基于点云数据的瘢痕长度测量方案

瘢痕鉴定是法医工作中重要的一项任务,对瘢痕的纹理、位置和长度等信息都有着细致的规定和要求。通过三维扫描仪可以便捷地获取点云数据,还原瘢痕区域的具体结构,为瘢痕鉴定提供新的工具。本文基于三维点云数据,提取瘢痕的趋势线,进行瘢痕长度测量。该方案首先对三维瘢痕数据进行投影,在二维平面上提取瘢痕的端点和关键点。然后在三维曲面上通过近邻搜索和向量内积的方法,依次连接所有关键点得到沿瘢痕表面的趋势线,计算瘢痕的长度。本文实验中使用的三维瘢痕点云来自某法医司法鉴定中心的工作内容,通过三维扫描仪提取。在实验数据上的应用结果显示,提取的趋势线在瘢痕表面贴合程度较好,可以跟随曲面进行弯折,可靠性很高。以点为核心的计算方法,在后续测量功能改进中也有较大的空间。     

数字图像处理技术在监控领域的应用

今天的人类生活在一个信息时代，图像是人类获取信息、表达信息和传递信息的重要手段。研究表明，在人类接受的信息中，图像等视觉信息所占的比重达到了75％。而与此同时我们又生活在一个数字时代，随着计算机技术及网络技术的迅速发展，几乎所有的信息都可以以数字的形式呈现在人们眼前。因此，在这样一个时代里，数字图像处理技术的研究和应用就已经成为现代生     

三维测量技术在人体损伤程度鉴定的应用探讨CSCD

体表损伤程度的鉴定是法医临床鉴定工作的一项重要任务,为刑事案件、民事纠纷等提供科学依据。体表创口的长度、挫擦伤及瘢痕的面积是人体损伤程度鉴定等级划分的客观证据,而其精确测量是法医临床实际鉴定工作的难点。三维测量技术的出现为体表损伤程度的准确检验提供可能。本文着重对三维测量技术在体表损伤程度鉴定实践工作中的应用进行探讨,以期提高司法鉴定的准确性、科学性、公正性。     

三维测量技术在人体损伤程度鉴定的应用探讨

体表损伤程度的鉴定是法医临床鉴定工作的一项重要任务,为刑事案件、民事纠纷等提供科学依据。体表创口的长度、挫擦伤及瘢痕的面积是人体损伤程度鉴定等级划分的客观证据,而其精确测量是法医临床实际鉴定工作的难点。三维测量技术的出现为体表损伤程度的准确检验提供可能。本文着重对三维测量技术在体表损伤程度鉴定实践工作中的应用进行探讨,以期提高司法鉴定的准确性、科学性、公正性。     

3DCity-Engine平台在智慧城市管理中的应用

<正>随着智慧城市建设的不断扩展和深入,3DGIS技术逐渐登上历史舞台,它可以应用在数字城市、城市综合管线管理、数字矿山、电力、水力、应急、海洋、军事等多个行业。基于3DCity-Engine形成的三维软件平台是新一代大型三维空间地理信息软件平台,在智慧城市管理中得到了很好的应用。     

Application of 3D Imaging Technology to Latent Fingermark Aging Studies

In most latent fingermark aging studies, two‐dimensional (2D) features are obtained from photo images, scans, or inked impressions. However, some relevant information is possibly being missed because fingermarks are three‐dimensional (3D) objects that age in all three dimensions. A feature that has not been carefully examined is how the height of ridges changes over time. In this report, a 3D imaging technology—called optical profilometry—is introduced as a tool for the visual examination of the aging process. Optical profilometry is a nondestructive technology that allows the visualization and data acquisition of unprocessed latent fingermarks. Detailed ridge images and spatiotemporal data were successively obtained on the x‐, y‐ and z‐axis, delivering 3D topographical information. OP was able to detect the loss of ridge heights over time. The feasibility of employing this technology to collect data on the aging process of ridges has been proven.     

多层螺旋CT与三维重建技术在法医损伤学中的应用

影像学技术发展迅速．已经成为临床诊断、治疗不可或缺的有效工具。利用MSCT与三维重建技术进行虚拟解剖,因为具有非破坏性、可显示特殊部位损伤形态、分析快速且便捷、便于证据保存和出示等特点在法医学尸体解剖中日益凸显优势．在法医损伤学研究及实践鉴定过程中具有较高的应用价值。文章综述了利用MSCT与三维重建技术在锐器伤、钝器伤、高坠伤、交通伤等实践领域的研究成果,并通过实践检案中遇到的典型案例,探讨多层螺旋CT与三维重建技术在法医学损伤鉴定中的应用价值。     

Haptics in forensics: The possibilities and advantages in using the haptic device for reconstruction approaches in forensic science

Non-invasive documentation methods such as surface scanning and radiological imaging are gaining in importance in the forensic field. These three-dimensional technologies provide digital 3D data, which are processed and handled in the computer. However, the sense of touch gets lost using the virtual approach. The haptic device enables the use of the sense of touch to handle and feel digital 3D data. The multifunctional application of a haptic device for forensic approaches is evaluated and illustrated in three different cases: the representation of bone fractures of the lower extremities, by traffic accidents, in a non-invasive manner; the comparison of bone injuries with the presumed injury-inflicting instrument; and in a gunshot case, the identification of the gun by the muzzle imprint, and the reconstruction of the holding position of the gun.The 3D models of the bones are generated from the Computed Tomography (CT) images. The 3D models of the exterior injuries, the injury-inflicting tools and the bone injuries, where a higher resolution is necessary, are created by the optical surface scan.The haptic device is used in combination with the software FreeForm Modelling Plus™ for touching the surface of the 3D models to feel the minute injuries and the surface of tools, to reposition displaced bone parts and to compare an injury-causing instrument with an injury.The repositioning of 3D models in a reconstruction is easier, faster and more precisely executed by means of using the sense of touch and with the user-friendly movement in the 3D space. For representation purposes, the fracture lines of bones are coloured. This work demonstrates that the haptic device is a suitable and efficient application in forensic science. The haptic device offers a new way in the handling of digital data in the virtual 3D space.     

Portable high‐resolution automated 3D imaging for footwear and tire impression capture

The forensic science community raised the need for improved evidence recognition, collection, and visualization analytical instrumentation for field and laboratory use. While the 3D optical techniques for imaging static objects have been extensively studied, there is still a major gap between current knowledge and collecting high‐quality footwear and tire impression evidence. Among optical means for 3D imaging, digital fringe projection (DFP) techniques reconstruct 3D shape from phase information, achieving camera‐pixel spatial resolution. This paper presents a high‐resolution 3D imaging technology using DFP techniques dedicated to footwear and tire impression capture. We developed fully automated software algorithms and a graphical user interface (GUI) that allow anyone without training to operate for high‐quality 3D data capture. We performed accuracy evaluations and comparisons comparing with the commercial high‐end 3D scanner and carried out qualitative tests for various impressions comparing with the current practices. Overall, our technology achieves similar levels of accuracy and resolution with a high‐end commercially available 3D scanner, while having the merits of being (1) more affordable; (2) much easier to operate; and (3) more robust. Compared with the current practice of casting, our technology demonstrates its superiority because it (1) is non‐destructive; (2) collects more evidence detail than casts, especially when an impression is fragile; (3) requires less time and money to collect each piece of evidence; and (4) results in a digital file that can easily be shared with other examiners.     

Development and Validation of a Virtual Examination Tool for Firearm Forensics, ,

The transition from 2D imaging to 3D scanning in the discipline of firearms and toolmark analysis is likely to provide examiners an unprecedented view of microscopic surface topography. The digital examination of measured 3D surface topographies has been referred to as virtual microscopy (VM). The approach offers several potential advantages over traditional comparison microscopy. Like any new analytic method, VM must be validated prior to its use in a crime laboratory. This paper describes one of the first validation studies of virtual microscopy. Fifty‐six participants at fifteen laboratories used virtual microscopic tools to complete two proficiency‐style tests for cartridge case identification. All participating trained examiners correctly reported 100% of the identifications (known matches) while reporting no false positives. The VM tools also allowed examiners to annotate compared surfaces. These annotations provide insight into the types of marked utilized in comparative analysis. Overall, the results of the study demonstrate that trained examiners can successfully use virtual microscopy to conduct firearms toolmark examination and support the use of the technology in the crime laboratory.     

Estimating Biological Characteristics With Virtual Laser Data

Laser scanning technology is increasingly being used in forensic anthropological research to obtain virtual data for archival purposes and post hoc measurement collection. This research compared the measurement accuracy of two laser scanners—the FARO Focus^3D 330X and the FARO Freestyle^3D—against traditionally obtained (i.e., by hand) control data (N = 454). Skeletal data were collected to address a novel question: the ability of laser scanning technology to produce measurements useful for biological characteristic estimation, such as sex and stature. Results indicate that both devices produced measurements very similar to control (c. 3‐mm average absolute error), but also illuminate a tendency to under‐measure. Despite these findings, the virtual data produced sex and stature estimates that varied little from control‐produced estimates, signifying the usefulness of virtual data for preliminary biological identification when the skeletal elements are no longer available for physical analysis.     

A Preliminary Investigation into the Accuracy of 3D Modeling and 3D Printing in Forensic Anthropology Evidence Reconstruction,

There is currently no published empirical evidence‐base demonstrating 3D printing to be an accurate and reliable tool in forensic anthropology, despite 3D printed replicas being exhibited as demonstrative evidence in court. In this study, human bones (n = 3) scanned using computed tomography were reconstructed as virtual 3D models (n = 6), and 3D printed using six commercially available printers, with osteometric data recorded at each stage. Virtual models and 3D prints were on average accurate to the source bones, with mean differences from ?0.4 to 1.2 mm (?0.4% to 12.0%). Interobserver differences ranged from ?5.1 to 0.7 mm (?5.3% to 0.7%). Reconstruction and modeling parameters influenced accuracy, and prints produced using selective laser sintering (SLS) were most consistently accurate. This preliminary investigation into virtual modeling and 3D printer capability provides a novel insight into the accuracy of 3D printing osteological samples and begins to establish an evidence‐base for validating 3D printed bones as demonstrative evidence.     

High-quality Digital 3D Reconstruction of Microscopic Findings in Forensic Pathology: The Terminal Pathway of a Heart Stab Wound*

High-quality digital three-dimensional (3D) reconstructions of microscopic findings have been used in anatomical and histopathologic research, but their use in forensic pathology may also be of interest. This paper presents an application of these methods to better characterize the pathway of a stab wound of the anterior surface of the heart in a case of suicide. A portion of the heart wall including the stab wound was serially sectioned for microscopic analysis along the full extent of the wound. Histologic sections were digitally acquired, and a 3D reconstruction was created with ImageJ software for 3D computer graphics. This showed a full-thickness wound path extending to the endocardial surface of the left ventricle, curvilinear in appearance. After correction for shrinkage, 3D reconstruction allowed estimation of the dimensions of the myocardial injury and comparison of the appearance of the wound with the suspected knife used. The curvilinear appearance was considered to reflect injury during myocardial contraction. Complete microscopic sectioning and 3D reconstruction may allow virtual sectioning through various orientations and also provide useful forensic information for selected injuries.