Szeneninterpretation unter Verwendung multimodaler Sensorik und Salienzmaßen

The work deals with aspects of image and video exploitation for monitoring, surveillance and security applications in non-cooperative application situations. The term "non-cooperative" refers to scenarios in which, for example, the recording parameters (backgrounds, lighting conditions, etc.) are not or hardly known. The goal is to detect man-made modifications (artifacts) in natural environments

Multi-Scale Vector-Ridge-Detection for Perceptual Organization Without Edges

We present a novel ridge detector that finds ridges on vector fields. It is designed to automatically find the right scale of a ridge even in the presence of noise, multiple steps and narrow valleys. One of the key features of such ridge detector is that it has a zero response at discontinuities. The ridge detector can be applied to scalar and vector quantities such as color. We also present a parallel perceptual organization scheme based on such ridge detector that works without edges; in addition to perceptual groups, the scheme computes potential focus of attention points at which to direct future processing. The relation to human perception and several theoretical findings supporting the scheme are presented. We also show results of a Connection Machine implementation of the scheme for perceptual organization (without edges) using color

Edge detection and ridge detection with automatic scale selection

When extracting features from image data, the type of information that can be extracted may be strongly dependent on the scales at which the feature detectors are applied. This article presents a systematic methodology for addressing this problem. A mechanism is presented for automatic selection of scale levels when detecting one-dimensional features, such as edges and ridges. Anovel concept of a scale-space edge is introduced, defined as a connected set of points in scale-space at which: (i) the gradient magnitude assumes a local maximum in the gradient direction, and (ii) a normalized measure of the strength of the edge response is locally maximal over scales. An important property of this definition is that it allows the scale levels to vary along the edge. Two specific measures of edge strength are analysed in detail. It is shown that by expressing these in terms of γ-normalized derivatives, an immediate consequence of this definition is that fine scales are selected for sharp edges (so as to reduce the shape distortions due to scale-space smoothing), whereas coarse scales are selected for diffuse edges, such that an edge model constitutes a valid abstraction of the intensity profile across the edge. With slight modifications, this idea can be used for formulating a ridge detector with automatic scale selection, having the characteristic property that the selected scales on a scale-space ridge instead reflect the width of the ridge

Szeneninterpretation unter Verwendung multimodaler Sensorik und Salienzmaßen

Die Arbeit behandelt video- bzw. bildgestützte Auswerteansätze für Anwendungen in der Sicherheitstechnik. Dazu werden ein flexibler und leicht erweiterbarer Ansatz zur Auffälligkeitsdetektion in Kombination mit Aspekten zur effizienten Implementierung sowie der integrative Rahmen eines Bildfolgenauswertesystems präsentiert. Die jeweils zu detektierende Auffälligkeit wird explizit durch die Angabe von Suchmustern definiert

Variations and Application Conditions Of the Data Type »Image« - The Foundation of Computational Visualistics

Few years ago, the department of computer science of the University Magdeburg invented a completely new diploma programme called 'computational visualistics', a curriculum dealing with all aspects of computational pictures. Only isolated aspects had been studied so far in computer science, particularly in the independent domains of computer graphics, image processing, information visualization, and computer vision. So is there indeed a coherent domain of research behind such a curriculum? The answer to that question depends crucially on a data structure that acts as a mediator between general visualistics and computer science: the data structure "image". The present text investigates that data structure, its components, and its application conditions, and thus elaborates the very foundations of computational visualistics as a unique and homogenous field of research. Before concentrating on that data structure, the theory of pictures in general and the definition of pictures as perceptoid signs in particular are closely examined. This includes an act-theoretic consideration about resemblance as the crucial link between image and object, the communicative function of context building as the central concept for comparing pictures and language, and several modes of reflection underlying the relation between image and image user. In the main chapter, the data structure "image" is extendedly analyzed under the perspectives of syntax, semantics, and pragmatics. While syntactic aspects mostly concern image processing, semantic questions form the core of computer graphics and computer vision. Pragmatic considerations are particularly involved with interactive pictures but also extend to the field of information visualization and even to computer art. Four case studies provide practical applications of various aspects of the analysis

Automatische Registrierung adaptiver Modelle zur Typerkennung technischer Objekte [online]

Anwendungen der Bildanalyse werden in zunehmendem Maße unter Verwendung dreidimensionaler Modelle realisiert und fusionieren auf diese Weise Methoden der Computergrafik und der Bildauswertung. Mit dem Ziel der automatischen Erfassung dynamischer Szenenaktivitäten ist in den letzten Jahren ein vermehrter Einsatz adaptiver Modelle zu beobachten. In der vorliegenden Arbeit wird ein neu entwickeltes Verfahren zur automatischen Konstruktion adaptiver Modelle für technische Objekte vorgestellt. Ferner werden Module zur automatischen Anpassung dieser adaptiven Modelle an Grauwertbilder beschrieben, die durch Synthese-Analyse-Iterationen die Brücke zur Bildanalyse schlagen. Die zentrale Stärke der vorgestellten Komponenten liegt darin, dass sie aus Einzelbildern dreidimensionale Rekonstruktionen für unbekannte Objektvarianten liefern. Wie experimentell gezeigt wird, sind diese Rekonstruktionen geometrisch genauer als handelsübliche Modelle. Die Leistungsfähigkeit der entwickelten Verfahren wird am Beispiel der Flugzeugtypisierung gezeigt. Darüber hinaus wird die Anwendbarkeit der Module zur Lageschätzung demonstriert