Colour Text Segmentation in Web Images Based on Human Perception

There is a significant need to extract and analyse the text in images on Web documents, for effective indexing, semantic analysis and even presentation by non-visual means (e.g., audio). This paper argues that the challenging segmentation stage for such images benefits from a human perspective of colour perception in preference to RGB colour space analysis. The proposed approach enables the segmentation of text in complex situations such as in the presence of varying colour and texture (characters and background). More precisely, characters are segmented as distinct regions with separate chromaticity and/or lightness by performing a layer decomposition of the image. The method described here is a result of the authors’ systematic approach to approximate the human colour perception characteristics for the identification of character regions. In this instance, the image is decomposed by performing histogram analysis of Hue and Lightness in the HLS colour space and merging using information on human discrimination of wavelength and luminance

Potential of wind turbines to elicit seizures under various meteorological conditions

Purpose: To determine the potential risk of epileptic seizures from wind turbine shadow flicker under various meteorologic conditions. Methods: We extend a previous model to include attenuation of sunlight by the atmosphere using the libradtran radiative transfer code. Results: Under conditions in which observers look toward the horizon with their eyes open we find that there is risk when the observer is closer than 1.2 times the total turbine height when on land, and 2.8 times the total turbine height in marine environments, the risk limited by the size of the image of the sun's disc on the retina. When looking at the ground, where the shadow of the blade is cast, observers are at risk only when at a distance <36 times the blade width, the risk limited by image contrast. If the observer views the horizon and closes their eyes, however, the stimulus size and contrast ratio are epileptogenic for solar elevation angles down to approximately 5°. Discussion: Large turbines rotate at a rate below that at which the flicker is likely to present a risk, although there is a risk from smaller turbines that interrupt sunlight more than three times per second. For the scenarios considered, we find the risk is negligible at a distance more than about nine times the maximum height reached by the turbine blade, a distance similar to that in guidance from the United Kingdom planning authorities. © 2009 International League Against Epilepsy

Multidimensional scaling reveals a color dimension unique to 'color-deficient' observers

Normal color vision depends on the relative rates at which photons are absorbed in three types of retinal cone:short-wave (S), middle-wave (M) and long-wave (L) cones, maximally sensitive near 430, 530 and 560nm, respectively. But 6% of men exhibit an X-linked variant form of color vision called deuteranomaly [1]. Their color vision is thought to depend on S cones and two forms of long-wave cone (L, L′) [2,3]. The two types of L cone contain photopigments that are maximally sensitive near 560nm, but their spectral sensitivities are different enough that the ratio of their activations gives a useful chromatic signal

Colour displays for categorical images

We propose a method for identifying a set of colours for displaying 2-D and 3-D categorical images when the categories are unordered labels. The principle is to find maximally distinct sets of colours. We either generate colours sequentially, to maximise the dissimilarity or distance between a new colour and the set of colours already chosen, or use a simulated annealing algorithm to find a set of colours of specified size. In both cases, we use a Euclidean metric on the perceptual colour space, CIE-LAB, to specify distances

S-cone signals invisible to the motion system can improve motion extraction via grouping by color

Peer reviewedPublisher PD

Phänomen Fernsehen - Freund oder Feind unserer Jugendlichen

Das Thema dieser Diplomarbeit beschäftigt sich mit dem Fernsehverhalten von jungen Heranwachsenden zwischen 16 und 18 Jahren. Genauer gesagt handelt es sich um die Fernsehgewohnheiten österreichischer Jugendlicher und Jugendlicher mit Migrationshintergrund. Die Untersuchung setzt sich aus insgesamt 100 Befragten zusammen (50 österreichische Jugendliche, 50 Jugendliche mit Migrationshintergrund). Der erste große Punkt der Arbeit beschäftigt sich mit der Charakteristik des Fernsehens, dessen Funktionen und Auswirkungen. Darauf folgt ein Vergleich der österreichischen und polnischen Medienlandschaft und eine exakte Analyse der österreichischen Rundfunksender ORF1 und ATV und der polnischen Sender TVP1 und TVN. Der zweite Punkt widmet sich der Realitätskonstruktion und der Wichtigkeit der Familie. Das wichtigste Thema in diesem Kapitel bezieht sich allerdings auf die Fernsehgewohnheiten von jungen Heranwachsenden mit Migrationshintergrund. Im dritten Punkt dieser Arbeit beschäftigt sich die Verfasserin mit dem Fernsehprogramm und gibt detaillierte Informationen über die ausgestrahlten Sendungen der bereits erwähnten Rundfunkanstalten. Im Zuge dieser Diplomarbeit werden daher folgende Fragen beantwortet: Was bieten die Rundfunkanstalten unseren Jugendlichen? Welche Programme rezipiert unsere Jugend? Nutzen Jugendliche mit Migrationshintergrund das Angebot der Programme in ihrer Muttersprache? Unterscheidet sich das Fernsehverhalten von österreichischen und polnischen Jugendlichen? Die Verfasserin dieser Diplomarbeit ist zu der Conclusio gekommen, dass Fernsehen nicht einfach als gut oder schlecht definiert werden kann. Unsere Jugend weiß sehr genau, wie sie mit dem Fernsehen umgehen soll und sucht sich die Programme bewusst aus. Trotz der Tatsache, dass das Fernsehen eine große Wichtigkeit im Alltag war, ist und bleiben wird, bevorzugen Jugendliche auch andere Freizeitaktivitäten. Weiters darf die Verantwortung nicht nur den Rundfunkanstalten zugeschrieben werden. Eltern, die gesamte Familiensituation und die Jugendlichen selber sind für ihr Fernsehverhalten verantwortlich

Lights, Camera, Action! Exploring Effects of Visual Distractions on Completion of Security Tasks

Human errors in performing security-critical tasks are typically blamed on the complexity of those tasks. However, such errors can also occur because of (possibly unexpected) sensory distractions. A sensory distraction that produces negative effects can be abused by the adversary that controls the environment. Meanwhile, a distraction with positive effects can be artificially introduced to improve user performance. The goal of this work is to explore the effects of visual stimuli on the performance of security-critical tasks. To this end, we experimented with a large number of subjects who were exposed to a range of unexpected visual stimuli while attempting to perform Bluetooth Pairing. Our results clearly demonstrate substantially increased task completion times and markedly lower task success rates. These negative effects are noteworthy, especially, when contrasted with prior results on audio distractions which had positive effects on performance of similar tasks. Experiments were conducted in a novel (fully automated and completely unattended) experimental environment. This yielded more uniform experiments, better scalability and significantly lower financial and logistical burdens. We discuss this experience, including benefits and limitations of the unattended automated experiment paradigm

Modern technologies production of cheese enriched with Omega - 3 fatty acids

Thermochromic films of MgxV1-xO2 were made by reactive dc magnetron   sputtering onto heated glass. The metal-insulator transition   temperature decreased by similar to 3 K/at. %Mg, while the optical   transmittance increased concomitantly. Specifically, the transmittance   of visible light and of solar radiation was enhanced by similar to 10%   when the Mg content was similar to 7 at. %. Our results point at the   usefulness of these films for energy efficient fenestration