首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
This system consists of a 3-D physiognomic range finder and a computer-assisted facial image superimposition unit. The 3-D range finder is composed of a detector for measuring facial surface and its control computer. The detector has two sinusoidal grating projection devices and two CCD cameras. The computer-assisted facial image superimposition unit consists of a host computer including a proprietary software, a flat surface color display and a color image scanner for inputting 2-D facial images of a criminal. The 3-D facial shape and texture of a suspect is obtained by using the range finder. To make the comparison between the 3-D facial image and the 2-D facial image, the 3-D facial image is first reproduced on a display of the host computer from a MO disk and then the 2-D facial image is taken with the color image scanner and reproduced on the display. The 3-D facial image is exactly adjusted to match the orientation and size of the 2-D facial image under the fine framework mode, and then the fine framework mode of 3-D facial image is converted to the fine texture image. The shape and positional relationships of facial components between the 3-D and 2-D facial images are examined by the fade-out or wipe image mode. The distance between the selected two points and angle among the selected three points on the 3-D and 2-D facial images are automatically measured for the assessment of anthropometrical data between both images. For evaluating the fit between the anthropometrical points on the 3-D and 2-D facial images, the reciprocal point-to-point difference between both images is compared.  相似文献   

2.
Identification from video surveillance systems is frequently requested in forensic practice. The "3D-2D" comparison has proven to be reliable in assessing identification but still requires standardization; this study concerns the validation of the 3D-2D profile comparison. The 3D models of the faces of five individuals were compared with photographs from the same subjects as well as from another 45 individuals. The difference in area and distance between maxima (glabella, tip of nose, fore point of upper and lower lips, pogonion) and minima points (selion, subnasale, stomion, suprapogonion) were measured. The highest difference in area between the 3D model and the 2D image was between 43 and 133 mm(2) in the five matches, always greater than 157 mm(2) in mismatches; the mean distance between the points was greater than 1.96 mm in mismatches, <1.9 mm in five matches (p < 0.05). These results indicate that this difference in areas may point toward a manner of distinguishing "correct" from "incorrect" matches.  相似文献   

3.
Photoanthropometry is a metric based facial image comparison technique. Measurements of the face are taken from an image using predetermined facial landmarks. Measurements are then converted to proportionality indices (PIs) and compared to PIs from another facial image. Photoanthropometry has been presented as a facial image comparison technique in UK courts for over 15 years. It is generally accepted that extrinsic factors (e.g. orientation of the head, camera angle and distance from the camera) can cause discrepancies in anthropometric measurements of the face from photographs. However there has been limited empirical research into quantifying the influence of such variables. The aim of this study was to determine the reliability of photoanthropometric measurements between different images of the same individual taken with different angulations of the camera. The study examined the facial measurements of 25 individuals from high resolution photographs, taken at different horizontal and vertical camera angles in a controlled environment. Results show that the degree of variability in facial measurements of the same individual due to variations in camera angle can be as great as the variability of facial measurements between different individuals. Results suggest that photoanthropometric facial comparison, as it is currently practiced, is unsuitable for elimination purposes. Preliminary investigations into the effects of distance from camera and image resolution in poor quality images suggest that such images are not an accurate representation of an individuals face, however further work is required.  相似文献   

4.
An improved method for DNA polymorphism typing of D1S80 VNTR locus and its application to paternity testing are described. For accurate estimation of the length of polymorphic DNA fragments, the size marker was labeled with fluorescence different from that of PCR primers, and co-electrophoresed as an internal standard. The dualcolour system of fluorescence image analyzer was used to detect the fragments and determine their size. This internal marker method could successfully overcome the problems of band pattern distortion and tailing, besides it allows easy and accurate interpretation of the DNA types. Our results indicate that the internal marker method is much more accurate than the method of using size marker in gel, even with the presence of distortion or tailing of the band patterns. Family studies applying this method showed complete agreement between the observed and predicated types.  相似文献   

5.
The feasibility of 2D-intensity and 3D-topography images from a non-invasive Chromatic White Light (CWL) sensor for the age determination of latent fingerprints is investigated. The proposed method might provide the means to solve the so far unresolved issue of determining a fingerprints age in forensics. Conducting numerous experiments for an indoor crime scene using selected surfaces, different influences on the aging of fingerprints are investigated and the resulting aging variability is determined in terms of inter-person, intra-person, inter-finger and intra-finger variation. Main influence factors are shown to be the sweat composition, temperature, humidity, wind, UV-radiation, surface type, contamination of the finger with water-containing substances, resolution and measured area size, whereas contact time, contact pressure and smearing of the print seem to be of minor importance. Such influences lead to a certain experimental variability in inter-person and intra-person variation, which is higher than the inter-finger and intra-finger variation. Comparing the aging behavior of 17 different features using 1490 time series with a total of 41,520 fingerprint images, the great potential of the CWL technique in combination with the binary pixel feature from prior work is shown. Performing three different experiments for the classification of fingerprints into the two time classes [0, 5h] and [5, 24h], a maximum classification performance of 79.29% (kappa=0.46) is achieved for a general case, which is further improved for special cases. The statistical significance of the two best-performing features (both binary pixel versions based on 2D-intensity images) is manually shown and a feature fusion is performed, highlighting the strong dependency of the features on each other. It is concluded that such method might be combined with additional capturing devices, such as microscopes or spectroscopes, to a very promising age estimation scheme.  相似文献   

6.
A new retrieval system for a 3D facial image database was designed and its reliability was experimentally examined. This system has two steps, firstly to automatically adjust the orientation of all 3D facial images in a database to that of the 2D facial image of a target person, and then to identify the facial image of the target person from the adjusted 3D facial images in the database using a graph-matching method. From the experimental study [M. Yoshino, K. Imaizumi, T. Tanijiri, J.G. Clement, Automatic adjustment of facial orientation in 3D face image database, Jpn. J. Sci. Tech. Iden. 8 (2003) 41-47], it is concluded that the software developed for the first step will be applicable to the automatic adjustment of facial orientation in the 3D facial image database. In 28 out of 110 sets (25.5%), the 3D image of the target person was chosen as the best match (from a database of 132 3D facial images) according to the similarity of the facial image characteristics based on the graph matching. The 3D facial image of the target person was ranked in the top of 10 of the database in 75 out of 110 sets (68.2%). These results suggest that this system is inadequate for the identification level, but may be feasible for screening method in a small database. It will be necessary to further pursue the possibility of realization of a facial image retrieval system for a large database such as suspects' facial images in future.  相似文献   

7.
The primary objective of this paper is to report on the successful implementation of forensic facial approximation in a real case in the forensic context. A three‐dimensional (3D) facial approximation protocol of the skull was performed with free software, applying techniques in a virtual environment that have already been consolidated in the literature. The skull was scanned with the photogrammetry technique, the digital replica was imported in the Blender software (Blender Foundation, Amsterdam) and individualized model sketches of the face were traced with the MakeHuman software (MakeHuman Org) according to the anthropological profile of the victim. The face created was imported in Blender, where it was adapted, modeled, and sculpted on the 3D skull and its soft tissue markers, using an American open‐source application of the technique in the digital environment. The face created in a virtual environment was recognized and legal identification procedures were started, resulting in the more agile delivery of the disappeared body to its next of kin. It is therefore concluded that facial approximation may not be a primary method of human identification, but it can be satisfactorily applied in the forensic field as an individual recognition resource. It has great value in narrowing the search, reducing the number of alleged victims, and leading to identification tests, therefore significantly reducing the number of genetic DNA (deoxyribonucleic acid) tests—which are considered costly for the State or Federation—and consequently reducing the waiting time before delivery of the body to its family.  相似文献   

8.
Facial reconstruction has until now been carried out by the sculpting technique. This method involves building a face with clay or other suitable material on to a skull or its cast, taking into account appropriate facial thickness measurements together with information provided by anthropologists such as approximate age, sex, race and other individual idiosyncrasies. A method for facial reconstruction is presented using 3-D computer graphics and is compared with the manual technique. The computer method involves initially digitising a skull using a laser scanner and video camera interfaced to a computer. A face, from a data bank which has previously digitised facial surfaces, is then placed over the skull in the form of a mask and the skin thickness is altered to conform with the underlying skull. The advantage of the computer method is its speed and flexibility. We have shown that the computer method for reconstructing a face is feasible and furthermore has the advantage over the manual technique of speed and flexibility. Nevertheless, the technique is far from perfect. Further facial thickness data needs collecting and the method requires evaluation using both known control skulls and later unknown remains.  相似文献   

9.
Footwear impressions are one of the most common forms of evidence to be found at a crime scene, and can potentially offer the investigator a wealth of intelligence. Our aim is to highlight a new and improved technique for the recovery of footwear impressions, using three-dimensional structured light scanning. Results from this preliminary study demonstrate that this new approach is non-destructive, safe to use and is fast, reliable and accurate. Further, since this is a digital method, there is also the option of digital comparison between items of footwear and footwear impressions, and an increased ability to share recovered footwear impressions between forensic staff thus speeding up the investigation.  相似文献   

10.
《Federal register》1999,64(88):24688
In accordance with the provisions of the Privacy Act, as amended, this notice announces a computer matching program that SSA plans to conduct with DOL.  相似文献   

11.
The paper describes the construction of a restriction profile of the Internal Transcribed Spacer II (ITS2) of Cannabis sativa L. Nuclear Ribosomal DNA, using digestion by a selected number of restriction endonucleases. The method was evaluated for false positives and it is suggested that it could be used to identify suspected Cannabis samples, by comparing their restriction profiles with the restriction profile of known Cannabis material.  相似文献   

12.
Amy2 phenotypes were determined by agarose gel electrophoresis on samples from 590 unrelated individuals. The frequencies of the allelic genes were found to be Amy12 0.9525, and Amy22 0.0475.  相似文献   

13.
Abstract: The gene encoding the dopamine D2 receptor (DRD2) has been suggested as a candidate gene for substance dependence. In this study, the possible association between Taq1A and Taq1B DRD2 polymorphisms and cannabinoid dependence was investigated. One hundred and twelve cannabinoid addicted and 130 healthy control subjects were included in this study. The Taq1A and Taq1B genotypes were determined in all subjects by polymerase chain reaction. For each polymorphism (A or B), the subjects were categorized into three groups according to their genotype, that is, the subjects with alleles A1/A1, A1/A2, A2/A2; B1/B1, B1/B2, and B2/B2. A significant association was found between Taq1A gene polymorphism and cannabinoid addicts compared to the control subjects. This finding suggests that polymorphism of the Taq1A, but not the Taq1B, may be associated with the susceptibility to cannabinoid dependence. Further clinical studies are required to be carried out for confirmation and evaluation of these findings.  相似文献   

14.
利用GC/MS检验致幻剂麦角酰二乙胺   总被引:1,自引:0,他引:1  
目的建立检验致幻剂麦角酰二乙胺的方法。方法用气相色谱与质谱联用仪(GC/MS)进行定性分析。结果麦角酰二乙胺质谱图保留时间为19.683min。结论该方法用于检案简单、可靠。  相似文献   

15.
A ribonuclease (RNase) was isolated from the urine of a 35-year-old male and purified to electrophoretic homogeneity. The enzyme was tentatively designated RNase 2. A rabbit antibody produced by injection of the purified RNase 2 was able to distinguish RNase 2 from another type of RNase coexisting in body fluids. With this antibody it was possible to detect RNase 2 isozymes in human serum and urine without difficulty using isoelectric focusing or sodium dodecyl sulfate-polyacrylamide gel electrophoresis, followed by immunoblotting. Both RNase 2 in serum and urine seemed to exist in multiple forms with regard to their molecular masses and pI values. This technique may prove to be useful in genetic and forensic studies of RNase polymorphism.  相似文献   

16.
A main goal of forensic medicine is to document and to translate medical findings to a language and/or visualization that is readable and understandable for judicial persons and for medical laymen. Therefore, in addition to classical methods, scientific cutting-edge technologies can and should be used. Through the use of the Forensic, 3-D/CAD-supported Photogrammetric method the documentation of so-called "morphologic fingerprints" has been realized. Forensic, 3-D/CAD-supported Photogrammetry creates morphologic data models of the injury and of the suspected injury-causing instrument allowing the evaluation of a match between the injury and the instrument. In addition to the photogrammetric body surface registration, the radiological documentation provided by a volume scan (i.e., spiral, multi-detector CT, or MRI) registers the sub-surface injury, which is not visible to Photogrammetry. The new, combined method of merging Photogrammetry and Radiology data sets creates the potential to perform many kinds of reconstructions and postprocessing of (patterned) injuries in the realm of forensic medical case work. Using this merging method of colored photogrammetric surface and gray-scale radiological internal documentation, a great step towards a new kind of reality-based, high-tech wound documentation and visualization in forensic medicine is made. The combination of the methods of 3D/CAD Photogrammetry and Radiology has the advantage of being observer-independent, non-subjective, non-invasive, digitally storable over years or decades and even transferable over the web for second opinion.  相似文献   

17.
The aim of the study was to improve the objectivity of X-ray image comparison for the identification of unknown dead individuals. CT-data were collected for 30 macerated skulls. An already presented computer program which uses CT data to establish virtual X-ray images was used to obtain X-rays with different beam angulations simulating rotation, dorsal flexion, and ventral flexion. Specific parameters were measured on the simulated images. The frontal sinus reveals the highest variability not only between the individual skulls but also within an individual skull in different positions. The most consistent parameters with respect to different positions were the skull breadth, the biorbital breadth and the bizygomatic breadth. In a blind study, three out of 24 skulls could clearly be identified just by measured distances although the positions were different and unknown to the investigator. The dimensions of the frontal sinus do not correlate with the other skull parameters (analysis of covariance). Based on the presented results, we propose a method that will calculate the probability of identity. The presented results demonstrate that the comparison of X-ray images can be undertaken in an objective way by quantifying the probability of identity even when the comparative images were made under different conditions.  相似文献   

18.
Forensic three-dimensional/computer aided design (CAD)-supported photogrammetry (FPHG) plays an important role in the field of the documentation of forensic relevant injuries; particularly so when a detailed, 3D reconstruction is necessary. This is demonstrated in the case of a patterned blunt injury to the face of a victim, which injury was subsequently proven by FPHG to have been caused by a blow from the muzzle of a soft air gun.The objects to be evaluated had to be series photographed in order to be evaluated virtually on the computer. These photo series were then analyzed with the RolleiMetric system. This system measures and calculates the spatial location of distinctive points on the objects' surfaces, and creates 3D data models of the objects. In a 3D/CAD program, the "virtual 3D model of the injury" is then compared against the "virtual 3D model of the possible injury-causing instrument".The validation of FPHG, as shown by the 3D match between certain characteristics of the muzzle form and the facial injury, demonstrates how this 3D method can be used for patterned wound documentation and analysis.  相似文献   

19.
Benzoylecgonine (BE) was detected in hair samples using nonproprietary extraction methodology and modifications of well-established radioimmunoassay (RIA) screening/quantitative gas chromatography/mass spectrometry (GC/MS) confirmation procedures. Samples collected anonymously from a population of 48 jail detainees weighed between 5.3 and 61.2 mg. All of the 22 hair samples which had RIA results indicating the presence of BE or immunologically similar substances above a cutoff amount of 1.25 ng/sample (50 ng/mL) were confirmed by GC/MS. Several varieties of hair color and texture were tested, although in each general category there were samples which contained BE as well as other samples which did not reveal detectable amounts of BE. The range of concentrations in 22 hair extracts that screened positive were 0.26 to 18 ng/mg hair as determined by GC/MS. In comparison with other reports of cocaine-related substances in hair, these data show consistent concentrations.  相似文献   

20.
GC/MS、GC/NPD法检测血液中氯胺酮   总被引:1,自引:1,他引:0  
目的利用GC/MS、GC/NPD与固相萃取(SPE)技术相结合,建立血液中氯胺酮的定性定量分析方法。方法选择4-苯基丁胺为内标,采用Bond-Elut Certify固相柱萃取、二氯甲烷:异丙醇:氨水(78∶20∶2,v/v/v)洗脱的固相萃取分离技术,比较不同pH体系、洗脱溶剂对回收率的影响,建立血液中氯胺酮的GC/MS、GC/NPD定性定量分析方法。结果以GC/NPD分析氯胺酮在6.0~5000ng/mL范围内线性关系良好,GC/MS-Scan定性检测限为20.0ng/mL。方法平均回收率达96.9%,标准偏差小于5%。结论此方法可满足氯胺酮毒品滥用者血液定性定量分析。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号