1,290 research outputs found
From Leaf to Litter : Nutrient resorption in a changing environment
No full textAerts, M.A.P.A. [Promotor]Toet, S. [Copromotor
Perceptual evaluation of colorized nighttime imagery
No full textWe recently presented a color transform that produces fused nighttime imagery with a realistic color appearance (Hogervorst & Toet, 2010, Information Fusion, 11-2, 69-77). To assess the practical value of this transform we performed two experiments in which we compared human scene recognition for monochrome intensified (II) and longwave infrared (IR) imagery, and color daylight (REF) and fused multispectral (CF) imagery. First we investigated the amount of detail observers can perceive in a short time span (the gist of the scene). Participants watched brief image presentations and provided a full report of what they had seen. Our results show that REF and CF imagery yielded the highest precision and recall measures, while both II and IR imagery yielded significantly lower values. This suggests that observers have more difficulty extracting information from monochrome than from color imagery. Next, we measured eye fixations of participants who freely explored the images. Although the overall fixation behavior was similar across image modalities, the order in which certain details were fixated varied. Persons and vehicles were typically fixated first in REF, CF and IR imagery, while they were fixated later in II imagery. In some cases, color remapping II imagery and fusion with IR imagery restored the fixation order of these image details. We conclude that color remapping can yield enhanced scene perception compared to conventional monochrome nighttime imagery, and may be deployed to tune multispectral image representation such that the resulting fixation behavior resembles the fixation behavior for daylight color imagery
Color image fusion for concealed weapon detection
No full textRecent advances in passive and active imaging sensor technology offer the potential to detect weapons that are concealed underneath a person's clothing or carried along in bags. Although the concealed weapons can sometimes easily be detected, it can be difficult to perceive their context, due to the non-literal nature of these images. Especially for dynamic crowd surveillance purposes it may be impossible to rapidly asses with certainty which individual in the crowd is the one carrying the observed weapon. Sensor fusion is an enabling technology that may be used to solve this problem. Through fusion the signal of the sensor that depicts the weapon can be displayed in the context provided by a sensor of a different modality. We propose an image fusion scheme in which non-literal imagery can be fused with standard color images such that the result clearly displays the observed weapons in the context of the original color image. The procedure is such that the relevant contrast details from the non-literal image are transferred to the color image without altering the original color distribution of this image. The result is a natural looking color image that fluently combines all details from both input sources. When an observer who performs a dynamic crowd surveillance task, detects a weapon in the scene, he will also be able to quickly determine which person in the crowd is actually carrying the observed weapon (e.g. the man with the red T-shirt and blue jeans). The method is illustrated by the fusion of thermal 8-12 µm imagery with standard RGB color images
A universal color image quality metric
No full textWe extend a recently introduced universal grayscale image quality index to a newly developed perceptually decorrelated color space. The resulting color image quality index quantifies the distortion of a processed color image relative to its original version. We evaluated the new color image quality metric through observer experiments in which subjects ranked images according to perceived distortion. The metric correlates strongly with human perception and can therefore be used to assess the performance of color image coding and compression schemes, color image enhancement algorithms, synthetic color image generators, and color image fusion schemes
A Universal Framework for Existence and State Transitions: The Theory of Every Thing (ToET)
No full textThis preprint introduces the Theory of Every Thing (ToET), a universal framework that adapts the Bloch sphere to model the spectrum of existence for any thing in the universe. By representing existence as a continuum from 0 (non-existence) to 1 (full existence), the ToET integrates principles of energy conservation, the golden ratio (φ), and fractal geometry to provide a unified mathematical foundation. Unlike previous unification attempts that focus solely on physical forces, ToET provides a mathematical language for describing state transitions across all disciplines and scales—from subatomic particles to galaxies, from single cells to ecosystems, from individual thoughts to societal movements. The theory demonstrates how numerous already-observed phenomena in nature, from phyllotaxis patterns to galactic structures, follow the mathematical relationships described by ToET. The ToET not only unifies physical and biological systems but also provides a mathematical foundation for understanding ethical dynamics and value optimization in societal systems. This paper presents evidence from existing literature validating the ToET’s predictions across multiple domains, establishing it as a comprehensive framework for understanding the existence and transition states of literally any thing that exists or could exist
Color the night : applying daytime colors to nighttime imagery
No full textWe present a method to give (fused) multiband night-time imagery a natural day-time color appearance. For input, the method requires a false color RGB image that is produced by mapping 3 individual bands (or the first 3 principal components) of a multiband nightvision system to the respective channels of an RGB image. The false color RGB nightvision image is transformed into a perceptually decorrelated color space. In this color space the first order statistics of a natural color image (target scene) are transferred to the multiband nightvision image (source scene). To obtain a natural color representation of the multiband night-time imagery, the compositions of the source and target scenes should resemble each other to some degree. The inverse transformation to RGB space yields a nightvision image with a day-time color appearance. The luminance contrast of the resulting color image can be enhanced by replacing its luminance component by a grayscale fused representation of the three input bands
Transferring color to single band intensified nightvision images
No full textWe present a method to give single band intensified nightvision imagery a natural day-time color appearance. For input, the method requires a true color RGB source image and a grayscale nightvision target image. The source and target image are both transformed into a perceptually decorrelated color space. In this color space a best matching source pixel is determined for each pixel of the target image. The matching criterion uses the first order statistics of the luminance distribution in a small window around the source and target pixels. Once a best matching source pixel is found, its chromaticity values are assigned (transferred) to the target pixel while the original luminance value of the target pixel is retained. The only requirement of the method is that the compositions of the source and target scenes resemble each other
Natural dynamic backgrounds affect perceived facial dominance
No full textWe have tested whether natural dynamic backgrounds affect perceived facial dominance. Facial evaluation is based on just two fundamental dimensions of facial appearance: valence and dominance. Perceived facial valence has been shown to be biased towards background valence. However, it is currently unknown, if the perception of facial dominance is also context dependent. In this study, participants rated the perceived dominance of neutral faces superimposed on everyday dynamic backgrounds that were either classified as low (weak) or high (strong) in dominance. Neutral faces were perceived as significantly more dominant when seen on a strong dynamic background than on either a weak or neutral background. Thus, background dominance enhances perceived facial dominance. Since dynamic textures are ubiquitous this finding is relevant for the design and experience of both our daily environment and multimedia content
Performance comparison of different graylevel image fusion schemes through a universal image quality index
No full textWe applied a recently introduced universal image quality index Q that quantifies the distortion of a processed image relative to its original version, to assess the performance of different graylevel image fusion schemes. The method is as follows. First, we adopt an original test image as the reference image. Second, we produce several distorted versions of this reference image. The distortions in the individual images are complementary, meaning that the same distortion should not occur at the same location in all images (it should be absent in at least one image). Thus, the information content of the overall set of distorted images should equal the information content of the original test image. Third, we apply the image fusion process to the set of distorted images. Fourth, we quantify the similarity of the fused image to the reference image by computing the universal image quality index Q. The method can also be used to optimize image fusion schemes for different types of distortions, by maximizing Q through repeated application of steps two and three for different parameter settings of the fusion scheme
Color remapping turns night into day
No full textA real-time mapping technique enables full-color rendering of multi-spectral nighttime images, making them as clear and colorful as daylight one
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