Auflistung nach Autor:in "Labudde, Dirk"
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- KonferenzbeitragAnalysing Distributions of Feature Similarities in the Context of Digital Anthropometric Pattern Matching Probability(INFORMATIK 2023 - Designing Futures: Zukünfte gestalten, 2023) Heinke, Florian; Heuschkel, Marie-Luise; Labudde, DirkDigital anthropometric pattern matching encompasses biometric identification on the basis of a combination of anthropometric measurements depicting the proportions of the human body from image or video material. In a previous publication, maximum likelihood density estimation of distributions of anthropometric measurement distances allowed for estimation of the probability of a match to be in the order of 10−15 to 10−8. However, the underlying nature and cause of these distributions remained unclear. This work represents an enhancement allowing for an analytical description of these distributions by assuming multivariate normals as distributions models, and by estimating distribution parameters that subsequently allow reasonable probability approximations. Thus the methodological groundwork presented here contributes to the evaluation of the probability for obtaining a match.
- KonferenzbeitragAnalysis of X-ray images of femora for age of death estimation of skeletal individuals(Biosig 2016, 2016) Jeraufke, Saskia; Pflugbeil, Anne-Marie; Becker, Sven; Schildbach, Stefan; Bruchhaus, Horst; Thiele, Karlheinz; Dreßler, Jan; Labudde, Dirk
- TextdokumentAutomated Determination of Fingerprint Ridge Density and Fingerprint Size to Detect Sex Differences(INFORMATIK 2021, 2021) Mohaupt, Marleen; Stoeter, Sieke; Labudde, DirkA fingerprint is probably the most important biometric feature when trying to link a suspect to a crime scene. So far, without a hit in a fingerprint database, it was impossible to use a collected fingerprint to narrow down the group of suspects. Moreover, in the existing studies about deriving phenotypic characteristics from fingerprints the analyses were done manually. In contrast, in this paper a procedure is presented to automatically determine the fingerprint ridge density and the fingerprint size, in order to derive information about the sex of the person the fingerprint belongs to. All 10 fingerprints of 140 individuals (70 males and 70 females) belonging to the German Caucasian population were secured and then analyzed. The best result was obtained for the ulnar area in combination with the fingerprint size of the left thumb with F1 measures of 0.84 (k-nearest neighbors algorithm - KNN), 0.833 (Support Vector Machine) and 0.817 (logistic regression).
- ZeitschriftenartikelAutomatic Classification of Bloodstains with Deep Learning Methods(KI - Künstliche Intelligenz: Vol. 36, No. 2, 2022) Bergman, Tommy; Klöden, Martin; Dreßler, Jan; Labudde, DirkThe classification of detected bloodstains into predetermined categories is a crucial component of the so-called bloodstain pattern analysis. As in other forensic disciplines, deep learning methods may help to reduce human subjectivity within this process, may increase the classification accuracy, shorten the calculation time and thus, enable high-throughput analysis. In this work, an approach is presented in which a convolutional neural network (Inception v3) was trained from 965 drip stains (passive origin) and 1595 blood spatters (active origin). The trained CNN was evaluated with a test data set consisting of 366 images of drip stains and blood spatters. The success rate was 99.73% which suggests that neural networks could also be used to automatically classify other classes of bloodstain patterns to speed up the investigation process in the future.
- ZeitschriftenartikelCOMBI: Artificial Intelligence for Computer-Based Forensic Analysis of Persons(KI - Künstliche Intelligenz: Vol. 36, No. 2, 2022) Becker, Sven; Heuschkel, Marie; Richter, Sabine; Labudde, DirkDuring the prosecution process the primary objective is to prove criminal offences to the correct perpetrator to convict them with legal effect. However, in reality this may often be difficult to achieve. Suppose a suspect has been identified and is accused of a bank robbery. Due to the location of the crime, it can be assumed that there is sufficient image and video surveillance footage available, having recorded the perpetrator at the crime scene. Depending on the surveillance system used, there could be even high-resolution material available. In short, optimal conditions seem to be in place for further investigations, especially as far as the identification of the perpetrator and the collection of evidence of their participation in the crime are concerned. However, perpetrators usually act using some kind of concealment to hide their identity. In most cases, they disguise their faces and even their gait. Conventional investigation approaches and methods such as facial recognition and gait analysis then quickly reach their limits. For this reason, an approach based on anthropometric person-specific digital skeletons, so-called rigs, that is being researched by the COMBI research project is presented in this publication. Using these rigs, it should be possible to assign known identities, comparable to suspects, to unknown identities, comparable to perpetrators. The aim of the COMBI research project is to study the anthropometric pattern as a biometric identifier as well as to make it feasible for the standardised application in the taking of evidence by the police and prosecution. The approach is intended to present computer-aided opportunities for the identification of perpetrators that can support already established procedures.
- KonferenzbeitragDevelopment and empirical optimization of an electrochemical analysis cell for the visualization of latent fingerprints and their chemical adhesives(BIOSIG 2020 - Proceedings of the 19th International Conference of the Biometrics Special Interest Group, 2020) Bergmann, Tommy; Gottschall, Sebastian; Fuchs, Enrico; Berlipp, Oliver; Labudde, DirkFingerprint analysis played a major role in the investigation of criminal offences for the past 100 years and is often the sole means of criminal identification [YA04]. Electrochemical analysis can yield important additional evidence like fingerprint age, biological age and gender of its creator as well as chemical adhesives [GRW12]. Additional gained characteristics through electrochemical analysis can supplement latent or incomplete fingerprints. In previous work a ruthenium-complex based solution was used as illuminant. Since luminol is readily available and is used in many forensic applications, the presented paper will focus on luminol as an alternative chemical for the ECL-aided visualization of fingerprints. Experiments were conducted by creating an electrochemical reaction inside a purpose build analysis cell. Eccrine, sebaceous glandlike and vaseline contaminated fingerprints were created on a stainless-steel plate placed inside the cell and investigated while applying direct current. Aim of this research was to investigate which kind of fingerprints can be visualized and which quality of the resulting images can be reached using luminol as illuminant. The used laboratory power supply created a strong light reaction at the start of each experiment revealing potential for further enhancement of the image quality. Eccrine dactyloscopic evidence showed no visible results. For sebaceous glandlike fingerprints age was discovered to significantly influence image quality.
- KonferenzbeitragThe digital skeleton in modern video analysis - inter- and intraspecific comparsionofindividualrigs(INFORMATIK 2023 - Designing Futures: Zukünfte gestalten, 2023) Pistorius, Elena; Richter, Sabine; Labudde, DirkNew methods for identifying individuals based on their digital skeleton (rig) gain attention in digital forensics. To ensure a solid comparison, understanding the development of this digital skeleton is crucial. One approach is manually creating a rig using a parametrized 3D room and cameras with embedded pictures, capturing multiple angles of the same person with markers on defined spots. Using these pictures and the room, a movable marker-based rig can be built in software like Blender (https://www.blender.org). It can be used to fit the rigged doll into another scene or compare proportions. For a similar process, algorithm-based software like OpenPose (https://github.com/CMU- Perceptual-Computing-Lab/openpose) estimates a digital skeleton from pictures or videos. The output includes JSON files with joint coordinates and pictures with embedded skeletons, which can manually be processsed into a rig. While these procedure can save time and expand applications, precision and supervision differ from marker-based rigs. A comparative study assessing similarity is discussed in the following paper.
- ZeitschriftenartikelDie Enkel von Locard(Informatik Spektrum: Vol. 44, No. 5, 2021) Povalej, Roman; Rittelmeier, Heiko; Fähndrich, Johannes; Berner, Silvio; Honekamp, Wilfried; Labudde, DirkDie seit Jahrhunderten verwendeten Methoden in der Forensik basieren auf der Annahme eines Austausches von Materie und Mustern. Durch die Digitalisierung sind diese Annahmen nur noch eingeschränkt gültig und werden hier erweitert und diskutiert. In dem Zusammenhang ist es erforderlich, den Spurenbegriff grundlegend zu überdenken. Gleichzeitig werfen der ständige technische Fortschritt und die immer größer werdende Flut von auszuwertenden Daten die Ermittlungsbehörden immer wieder zurück. Dieser Entwicklung ist nur durch Automatisierung Herr zu werden. Verfahren der Künstlichen Intelligenz können und werden die Ermittlungsbehörden zukünftig dabei zunehmend unterstützen.
- TextdokumentHypothesis-driven Case Analysis in 3D-Space as a Support for Forensic Casework(INFORMATIK 2021, 2021) Becker, Sven; Bergmann, Tommy; Peldschus, Steffen; Labudde, DirkInterpreting the evidence found at a crime scene is essential in reconstructing the circumstances of a crime and, hence, solving it. In this paper a classical hypothesis-driven approach is combined with computer-aided modeling. Hereby, the paper focuses on the advantages of 3D models and their added value in the reconstruction of a case by visually supporting the analysis of evidence found at a crime scene. Using the example of blood patterns, it is explained what the static part of an evidence is and how the interpretation of this part, with the help of an interpretation function, results in additional information about the dynamic part of evidence. Further it is explained how this concept can assist the classical hypothesis-driven approach of reconstructing a crime. By using 3D models it is possible to improve the analysis of the formation of evidence and especially the time line. Thus, 3D-models can aid classical forensic casework with a new computer-based approach.
- KonferenzbeitragMöglichkeiten, Grenzen und Konzepte für eine digitalbasierte Täterbewertung im Bereich der §§ 174 – 184(INFORMATIK 2023 - Designing Futures: Zukünfte gestalten, 2023) Steinert, Mirijam; Herchel, Sabrina; Labudde, DirkIm Zusammenhang mit Straftaten gegen die sexuelle Selbstbestimmung (§§ 174 - 184) kommt es üblicherweise zu einer Auswertung von digitalen Beweismitteln. Diese Datenmengen wachsen stetig. Durch die Zusammenführung aller verfügbaren Daten innerhalb des Verfahrens ergeben sich neue Chancen, um weitere Erkenntnisse zu gewinnen. Bei der Analyse von Datenträgern werden vorwiegend multimediale Inhalte wie Bilder, Videos und Chatnachrichten ausgewertet und in einem Gutachten verschriftlicht. Oftmals stellt sich die Frage, wie hoch das Gefährdungspotenzial durch den Beschuldigten ist. Bei der Begutachtung von Sexualstraftätern werden Risikoanalysen durchgeführt. Aus welchen Elementen der verfügbaren digitalen Daten können bei der Risikobewertung von Sexualstraftätern Schlüsse gezogen werden und ergeben sich dabei weitere Möglichkeiten der Risikobewertung? Kann ein Täterprofil bei hinreichender Nutzeridentifizierung (Täter = Nutzer) auf Basis der verfügbaren digitalen Daten automatisiert erstellt werden, und welche spezifischen Informationen sind dafür relevant? Welche gesetzlichen und technischen Einschränkungen müssen bei der Beantwortung dieser Fragen beachtet werden, und welche Risiken sind damit verbunden?