Internal Perspectivalism: The Solution to Generality Problems About Proper Function and Natural Norms

In this paper, I argue that what counts as the proper function of a trait is a matter of the de facto perspective that the biological system, itself, possesses on what counts as proper functioning for that trait. Unlike non-perspectival accounts, internal perspectivalism does not succumb to generality problems. But unlike external perspectivalism, internal perspectivalism can provide a fully naturalistic, mind-independent grounding of proper function and natural norms. The attribution of perspectives to biological systems is intended to be neither metaphorical nor anthropomorphic: I do not mean to imply that such systems thereby must possess agency, cognition, intentions, concepts, or mental or psychological states. Instead, such systems provide the grounding for norms of performance when they internally enforce their own standard of (i.e., their own perspective on) what constitutes proper functioning or malfunctioning. By operating with a fixed, determinate level of generality, such systems provide the basis for an account of proper function that is immune to generality problems

Constraints for Time-Multiplexed Structured Light with a Hand-held Camera

Multi-frame structured light in projector-camera systems affords high-density and non-contact methods of 3D surface reconstruction. However, they have strict setup constraints which can become expensive and time-consuming. Here, we investigate the conditions under which a projective homography can be used to compensate for small perturbations in pose caused by a hand-held camera. We synthesize data using a pinhole camera model and use it to determine the average 2D reprojection error per point correspondence. This error map is grouped into regions with specified upper-bounds to classify which regions produce sufficiently minimal error to be considered feasible for a structured-light projector-camera system with a hand-held camera. Empirical results demonstrate that a sub-pixel reprojection accuracy is achievable with a feasible geometric constraint

A feasibility study on the use of agent-based image recognition on a desktop computer for the purpose of quality control in a production environment

Thesis (M. Tech.) - Central University of Technology, Free State, 2006A multi-threaded, multi-agent image recognition software application called RecMaster has been developed specifically for the purpose of quality control in a production environment. This entails using the system as a monitor to identify invalid objects moving on a conveyor belt and to pass on the relevant information to an attached device, such as a robotic arm, which will remove the invalid object. The main purpose of developing this system was to prove that a desktop computer could run an image recognition system efficiently, without the need for high-end, high-cost, specialised computer hardware. The programme operates by assigning each agent a task in the recognition process and then waiting for resources to become available. Tasks related to edge detection, colour inversion, image binarisation and perimeter determination were assigned to individual agents. Each agent is loaded onto its own processing thread, with some of the agents delegating their subtasks to other processing threads. This enables the application to utilise the available system resources more efficiently. The application is very limited in its scope, as it requires a uniform image background as well as little to no variance in camera zoom levels and object to lens distance. This study focused solely on the development of the application software, and not on the setting up of the actual imaging hardware. The imaging device, on which the system was tested, was a web cam capable of a 640 x 480 resolution. As such, all image capture and processing was done on images with a horizontal resolution of 640 pixels and a vertical resolution of 480 pixels, so as not to distort image quality. The application locates objects on an image feed - which can be in the format of a still image, a video file or a camera feed - and compares these objects to a model of the object that was created previously. The coordinates of the object are calculated and translated into coordinates on the conveyor system. These coordinates are then passed on to an external recipient, such as a robotic arm, via a serial link. The system has been applied to the model of a DVD, and tested against a variety of similar and dissimilar objects to determine its accuracy. The tests were run on both an AMD- and Intel-based desktop computer system, with the results indicating that both systems are capable of efficiently running the application. On average, the AMD-based system tended to be 81% faster at matching objects in still images, and 100% faster at matching objects in moving images. The system made matches within an average time frame of 250 ms, making the process fast enough to be used on an actual conveyor system. On still images, the results showed an 87% success rate for the AMD-based system, and 73% for Intel. For moving images, however, both systems showed a 100% success rate

Improving SLI Performance in Optically Challenging Environments

The construction of 3D models of real-world scenes using non-contact methods is an important problem in computer vision. Some of the more successful methods belong to a class of techniques called structured light illumination (SLI). While SLI methods are generally very successful, there are cases where their performance is poor. Examples include scenes with a high dynamic range in albedo or scenes with strong interreflections. These scenes are referred to as optically challenging environments. The work in this dissertation is aimed at improving SLI performance in optically challenging environments. A new method of high dynamic range imaging (HDRI) based on pixel-by-pixel Kalman filtering is developed. Using objective metrics, it is show to achieve as much as a 9.4 dB improvement in signal-to-noise ratio and as much as a 29% improvement in radiometric accuracy over a classic method. Quality checks are developed to detect and quantify multipath interference and other quality defects using phase measuring profilometry (PMP). Techniques are established to improve SLI performance in the presence of strong interreflections. Approaches in compressed sensing are applied to SLI, and interreflections in a scene are modeled using SLI. Several different applications of this research are also discussed

The Mechanistic and Normative Structure of Agency

I develop an interdisciplinary framework for understanding the nature of agents and agency that is compatible with recent developments in the metaphysics of science and that also does justice to the mechanistic and normative characteristics of agents and agency as they are understood in moral philosophy, social psychology, neuroscience, robotics, and economics. The framework I develop is internal perspectivalist. That is to say, it counts agents as real in a perspective-dependent way, but not in a way that depends on an external perspective. Whether or not something counts as an agent depends on whether it is able to have a certain kind of perspective. My approach differs from many others by treating possession of a perspective as more basic than the possession of agency, representational content/vehicles, cognition, intentions, goals, concepts, or mental or psychological states; these latter capabilities require the former, not the other way around. I explain what it means for a system to be able to have a perspective at all, beginning with simple cases in biology, and show how self-contained normative perspectives about proper function and control can emerge from mechanisms with relatively simple dynamics. I then describe how increasingly complex control architectures can become organized that allow for more complex perspectives that approach agency. Next, I provide my own account of the kind of perspective that is necessary for agency itself, the goal being to provide a reference against which other accounts can be compared. Finally, I introduce a crucial distinction that is necessary for understanding human agency: that between inclinational and committal agency, and venture a hypothesis about how the normative perspective underlying committal agency might be mechanistically realized

Methoden zur Reduktion der Messlatenz von GOBO-Projektor-basierten 3D-Sensoren

Genaue, optische 3D-Messverfahren werden vielfältig in der Industrie, der Medizin und der Wissenschaft eingesetzt. Bei etlichen dieser Anwendungen ist eine schnelle Reaktion auf Veränderungen in der Messszene erforderlich. Dies ist z.B. der Fall, wenn eine Maschine aus Sicherheitsgründen abgeschaltet oder angehalten werden muss oder eine direkte Rückmeldung an einen Menschen gegeben werden soll. Steht das 3D-Ergebnis der Messung nach hinreichend kurzer Zeit ab Beginn der Messung zur Verfügung, kann die Reaktion basierend auf diesem Ergebnis angestoßen werden. Das Prinzip des GOBO-Projektor-basierten, aktiven Stereo-Sensors hat sich als genaues, optisches 3D-Messverfahren etabliert. Bei diesem Verfahren wird ein sich zeitlich änderndes, aperiodisches Streifenmuster auf das Messobjekt projiziert, während zwei kalibrierte Kameras jeweils eine Bildsequenz synchron aufnehmen. Innerhalb dieser Bildsequenzen werden anschließend die Abbilder von Objektpunkten, welche in beiden Kameras sichtbar sind, einander zugeordnet. Für jedes solche Paar wird dann die 3D-Koordinate des zugehörenden Objektpunktes trianguliert. Das Verfahren erlaubt auch 3D-Aufnahmen mit speziellen Anforderungen, die von anderen, genauen 3D-Sensorprinzipien nur schwer erreicht werden. Dazu gehört die Messung mit speziellen Lichtwellenlängen, wie z.B. dem Nah-Infrarotbereich, womit blendfreie Vermessung ermöglicht wird, oder die Erfassung sehr schneller Prozesse, wie die Messung von Airbag-Entfaltungen. Bisher war es jedoch nicht möglich, die 3D-Messergebnisse in so kurzer Zeit (z.B. 100 ms), d.h. mit so kurzer Messlatenz, zur Verfügung zu stellen, dass eine unmittelbare Reaktion auf eine Veränderung der Messszene erfolgen kann. Diese Verkürzung der Messlatenz ist das Ziel dieser Arbeit. Es werden Methoden beschrieben und untersucht, mit denen die Messlatenz von GOBO-Projektor-basierten, aktiven Stereo-Sensoren auf unter 100 ms verkürzt werden kann. Die Verbesserungen konzentrieren sich auf zwei Bereiche: die schnelle Rekonstruktion des 3D-Modells aus den aufgenommenen Bildsequenzen und die Reduktion der Aufnahmezeit durch Verkürzung der Bildsequenz-Länge. Letztere wird mittels einer Optimierung der Musterprojektion ermöglicht, welche bei kurzen Bildsequenz-Längen eine erhebliche Reduktion unerwünschter Messartefakte bewirkt. Abschließend werden mehrere Anwendungen gezeigt, die von diesen Verbesserungen profitieren.Accurate, optical 3D measurement techniques are widely used in industry, medicine and science. In some of the applications, a fast response to changes in the measurement scene is required. This is the case, for example, when a machine has to be stopped to avoid collision, or direct feedback to a human being must be provided. If the 3D result of the measurement is available after a sufficiently short time from the start of the measurement, the reaction can be triggered based on this result. Active stereo 3D sensors based on GOBO projection have been established as an accurate optical 3D measurement method. The sensor projects a time-varying, aperiodic fringe pattern onto the measured object, while two calibrated cameras synchronously record an image sequence, each. After the recording, a 3D reconstruction algorithm searches for pixels pairs, which correspond to the same object point within these two image sequences. For each such pair, the algorithm triangulates the 3D coordinate of the associated object point. With this method, special requirements can be accounted for which are difficult to achieve by other accurate 3D measurement principles. These include measurements with special light wavelengths, such as the near-infrared range, thus enabling glarefree, i.e. irritation-free measurement, or the measurement of very fast processes, such as the measurement of airbag inflation. Until now, however, it has not been possible to provide 3D measurement results in such a short time (e.g. 100ms), i.e. with such a short measurement latency, that an immediate reaction to a change in the measurement scene can be made. Therefore, the goal of this dissertation is the reduction of the measurement latency. In this dissertation, the author describes and investigates methods to shorten the measurement latency of GOBO projector-based active stereo sensors to less than 100ms. The improvements focus on two areas: fast reconstruction of the 3D model from the acquired image sequences, and reduction of the acquisition time by shortening the image sequence length. The latter is achieved by means of an optimization of the pattern projection, which results in a significant reduction of unwanted measurement artifacts for short image sequence lengths. Finally, the author shows several applications that benefit from these improvements