Kimberly Lane

Fuzzy-logic-based sensor fusion for mine and concealed weapon detection

The use of near, mid wavelength and long wavelength infrared imagery for the detection of mines and concealed weapons is demonstrated using several techniques. The fusion algorithms used are wavelet based fusion and Fuzzy Logic Approach (FLA) fusion. The FLA is presented as one of several possible methods for combining images from different sensors for achieving an image that displays more information than either image separately. Metrics are suggested that could rate the fidelity of the fused images, such as, an entropy metric.

Fuzzy-logic-based sensor fusion of images

The fusion of visual and infrared sensor images of potential driving hazards in static infrared and visual scenes is computed using the Fuzzy Logic Approach (FLA). The FLA is presented as a new method for combining images from different sensors for achieving an image that displays more information than either image separately. Fuzzy logic is a modeling approach that encodes expert knowledge directly and easily using rules. With the help of membership functions designed for the data set under study, the FLA can model and interpolate to enhance the contrast of the imagery. The Mamdani model is used to combine the images. The fused sensor images are compared to metrics to measure the increased perception of a driving hazard in the sensor-fused image. The metrics are correlated to experimental ranking of the image quality. A data set containing IR and visual images of driving hazards under different types of atmospheric contrast conditions is fused using the Fuzzy Logic Approach (FLA). A holographic matched-filter method (HMFM) is used to scan some of the more difficult images for automated detection. The image rankings are obtained by presenting imagery in the TARDEC Visual Perception Lab (VPL) to subjects. Probability of detection of a driving hazard is computed using data obtained in observer tests. The matched-filter is implemented for driving hazard recognition with a spatial filter designed to emulate holographic methods. One of the possible automatic target recognition devices implements digital/optical cross-correlator that would process sensor-fused images of targets. Such a device may be useful for enhanced automotive vision or military signature recognition of camouflaged vehicles. A textured clutter metric is compared to experimental rankings.

Noise and contrast comparison of visual and infrared images of hazards as seen inside an automobile

The purpose of this experiment was to quantitatively measure driver performance for detecting potential road hazards in visual and infrared (IR) imagery of road scenes containing varying combinations of contrast and noise. This pilot test is a first step toward comparing various IR and visual sensors and displays for the purpose of an enhanced vision system to go inside the driver compartment. Visible and IR road imagery obtained was displayed on a large screen and on a PC monitor and subject response times were recorded. Based on the response time, detection probabilities were computed and compared to the known time of occurrence of a driving hazard. The goal was to see what combinations of sensor, contrast and noise enable subjects to have a higher detection probability of potential driving hazards.

Eyetracker analysis of fixation points using an IR HUD in an automobile

This paper describes the experimental apparatus and analysis techniques now in place at the US Army Tank-automotive and Armaments COMmand Visual Perception Lab in Warren, Michigan, and the results of some preliminary trials using these methods. The tools will be used to develop and analyse experiments to better understand how drivers use various displays and viewing systems intended to aid drivers in poor visibility conditions, particularly at night. Visible and infrared road scene imagery obtained from the field were displayed simultaneously and subject eye fixation and point of gaze measured using a magnetic head tracker and near infrared eyetracker. Results were analysed to determine if personal differences between the various subjects caused them to prefer one display to another. The goal was to see if people prefer to use the heads up display or the direct view for driving at night.

Use of a photosimulation laboratory for estimating vehicle detection probability

Abstract : A method is described for using a photosimulation laboratory environment to compare detection metrics and evaluate the effectiveness of camouflage for military vehicles. There are distinct advantages to acquiring images at the field site and then bringing them back to a laboratory environment for observer testing versus taking the subjects out to the field for estimating detection probability. Laboratory testing using field acquired imagery provides a repeatable, secure, and relatively low-cost way to generate consistent data for the measurement of the effectiveness of camouflage relative to a baseline vehicle, and the calibration and validation of target acquisition models. A laboratory test procedure is described by the authors in which a baseline Light Armored Vehicle (LAV) is compared to a treated LAV in the TACOM Visual Perception Laboratory (VPL) using imagery collected from the field in the manner prescribed by an experimental design.

Design and Perception Testing of a Novel 3-D Autostereoscopic Holographic Display System

US Army Tank-Automotive Command researchers are in the early stages of developing an autostereoscopic, 3D holographic visual display system. The present system uses holographic optics, low and high-resolution optics, low and high- resolution projectors, and computer workstation graphics to achieve real-time, 3D user-interactivity. This system is being used to conduct 3D visual perception studies for the purpose of understanding the effects of 3D in military target visual detection and as an alternative technique to CAD model visualization. The authors describe the present system configuration, operation, some of the technical limitations encountered during the system development, and the result of a human perception test that compared subject response times, hit rates and miss rates of visual detection when subjects used conventional 2D methods versus the 3D holographic image produced by the holographic display system. The results of this study revealed that 3D HOE system increased the perception of accuracy of moving vehicles. This research has provided some insights into which technology will be the best for presenting 3D simulated objects to subjects or designers in the laboratory.

Comparison of 2D and 3D displays and sensor fusion for threat detection, surveillance and telepresence

Visible, infrared (IR) and sensor-fused imagery of scenes that contain occluded camouflaged threats are compared on a two dimensional (2D) display and a three dimensional (3D) display. A 3D display is compared alongside a 2D monitor for hit and miss differences in the probability of detection of objects. Response times are also measured. Image fusion is achieved using a Gaussian Laplacian pyramidal approach with wavelets for edge enhancement. Detecting potential threats that are camouflaged or difficult to see is important not only for military acquisition problems but, also for crowd surveillance as well as tactical use such as on border patrols. Imaging and display technologies that take advantage of 3D and sensor fusion will be discussed.