Scene-based imperceptible-visible watermarking for HDR video content

This paper presents the High Dynamic Range - Imperceptible Visible Watermarking for HDR video content (HDR-IVW-V) based on scene detection for robust copyright protection of HDR videos using a visually imperceptible watermarking methodology. HDR-IVW-V employs scene detection to reduce both computational complexity and undesired visual attention to watermarked regions. Visual imperceptibility is achieved by finding the region of a frame with the highest hiding capacities on which the Human Visual System (HVS) cannot recognize the embedded watermark. The embedded watermark remains visually imperceptible as long as the normal color calibration parameters are held. HDR-IVW-V is evaluated on PQ-encoded HDR video content successfully attaining visual imperceptibility, robustness to tone mapping operations and image quality preservation

Supporting Focus and Context Awareness in 3D Modeling Using Multi-Layered Displays

Although advances in computer technology over the past few decades have made it possible to create and render highly realistic 3D models these days, the process of creating these models has remained largely unchanged over the years. Modern 3D modeling software provide a range of tools to assist users with creating 3D models, but the process of creating models in virtual 3D space is nevertheless still challenging and cumbersome. This thesis, therefore, aims to investigate whether it is possible to support modelers more effectively by providing them with alternative combinations of hardware and software tools to improve their 3D modeling tasks. The first step towards achieving this goal has been to better understand the type of problems modelers face in using conventional 3D modeling software. To achieve this, a pilot study of novice 3D modelers, and a more comprehensive study of professional modelers were conducted. These studies resulted in identifying a range of focus and context awareness problems that modelers face in creating complex 3D models using conventional modeling software. These problems can be divided into four categories: maintaining position awareness, identifying and selecting objects or components of interest, recognizing the distance between objects or components, and realizing the relative position of objects or components. Based on the above categorization, five focus and context awareness techniques were developed for a multi-layer computer display to enable modelers to better maintain their focus and context awareness while performing 3D modeling tasks. These techniques are: object isolation, component segregation, peeling focus, slicing, and peeling focus and context. A user study was then conducted to compare the effectiveness of these focus and context awareness techniques with other tools provided by conventional 3D modeling software. The results of this study were used to further improve, and evaluate through a second study, the five focus and context awareness techniques. The two studies have demonstrated that some of these techniques are more effective in supporting 3D modeling tasks than other existing software tools

HPC Enhanced Large Urban Area Evacuation Simulations with Vision based Autonomously Navigating Multi Agents

AbstractAn evacuation simulation code based on Multi Agent Systems (MAS), with moderately complex agents in 2D grid envi- ronments, is developed. The main objective of this code is to estimate the effectiveness of the measures taken to smoothen and speedup the evacuation process of a large urban area, in time critical events like tsunami. A vision based autonomous navigation algorithm, which enables the agents to move through an urban environment and reach a far visible destination, is implemented. This simple algorithm enables a visitor agent to navigate through urban area and reach a destination which is several kilometers away. The navigation algorithm is verified comparing the simulated evacuation time and the paths taken by individual agents with those of theoretical. Further, a parallel computing extension is developed for studying mass evacuation of large areas; vision based autonomous navigation is computationally intensive. Several strategies like communication hiding, dynamic load balancing, etc. are implemented to attain high parallel scalability. Preliminary tests on the K-computer attained strong scalability above 94% at least up to 2048 CPU cores, with 2 million agents

Summary of Coral Cay Conservation's habitat mapping data from Utila, Honduras

IIThe coral reefs of Honduras are of vital national and international importance,both ecologically and economically, but are threatened because of rapid economicand population growth.? During work on Utila between 1999 and 2000 (the ?Bay Islands 2000? project),Coral Cay Conservation developed a programme of surveys, training andconservation education aimed at assessing the status of local reefs and improvingenvironmental awareness amongst neighbouring communities.? This summary report provides an overview of the habitat mapping data collectedby the Bay Islands 2000 project.? CASA provided software, hardware and skills, on a charitable basis to ensure thatthe data collected by CCC could be developed into a GIS, not only for mappingthe status of the coral reefs of Honduras, but also to provide analysis of the aerialextent of these reefs.? Data were collected within individual ?study areas?, to facilitate analysis at a rangeof spatial scales, and utilised the CCC standard baseline survey technique for therapid assessment of the characteristics of reef communities. The surveys,therefore, utilised a series of transects, perpendicular to the reef.? Baseline transects discriminated nine benthic and six geomorpholgical classeswhich indicates Utila has a high habitat diversity. Habitat diversity is importantsince the number of habitat types has been shown to be a good representation ofspecies biodiversity.? The nine benthic classes that were distinguished were all relatively coral poorbecause of a suite of relatively long-term local and regional factors, exacerbatedby the combination of Hurricane Mitch and coral bleaching in 1995 and 1998.? Damselfish were the most abundant reef associated fish recorded during baselinetransect surveys. Commercially important fish were less abundant that wouldnormally be expected in unfished systems.? A recurring pattern in the baseline transect data was the greater abundance anddiversity of fish in coral rich classes. However, although the link between fishabundance and coral cover was clear, not all species were necessarily mostabundant in the most coral rich areas.? Invertebrates were generally uncommon, partly because of fishing pressure, andthe abundances of many invertebrate taxa were correlated with coral cover.? A habitat map is presented within this report as an indication of the distribution ofhabitat types around Utila.? Using the map, estimates of areal extents of each benthic class and habitat type areinstructive. For example, there is only approximately 27 km2 of reefal habitatsaround Utila. Furthermore, the area supporting the most coral rich benthic classesis only approximately 4 km2 (15%). These statistics both highlight the damagecaused by the bleaching event and Hurricane Mitch and other anthropogenicimpacts and the need to conserve remaining coral rich areas.? If further reserves were to be created, it would be important to try to protect arange of reef and habitat types. For this reason, it appears that the Turtle HarbourWildlife Refuge is well placed since this areas includes a wide range of habitattypes. However, placement of reserves in Utila should favour relatively coral richhabitats over sand dominated areas.? This study led to six recommendations:Summary Utila habitat mapping reportIII? One or more agencies should collect additional ground-truthing data fromaround Utila to facilitate both classification of currently ?Unknown? polygonsand an accuracy assessment of the map.? Establish an integrated GIS and associated meta-database for Utila, includingdata from the Bay Islands 2000 project.? Examine the potential of using data collected by the Bay Islands 2000 projectas the basis of national habitat classification scheme and subsequent nationalhabitat map.? Continue to aim to establish one or more additional multiple use marineprotected areas around Utila, with an integrated monitoring programme tomeasure their efficacy, and strengthen the enforcement of regulations in theTurtle Harbour Wildlife Sanctuary. Establish regulations, and enforce existinglegislation, to minimise the detrimental effects of coastal development on reefhealth.? Additional marine reserves in Utila should integrate factors such as thepreference of many fish species for coral rich habitats and the protection ofareas incorporating a range of habitat types, including mangroves and seagrassbeds, in order to allow for nursery areas, ontogenetic shifts and species thatrely on non-coral rich habitats. The corollary of the preference of fish speciesfor coral rich habitats is to protect coral cover within the reserves.? The reef on the south coast of Utila appears to be a good candidate forprotection because it is relatively sheltered from storm and hurricane damage

Escondiendo puntos en espirales e histogramas

El problema de maximizar el número de vértices que no son visibles dos a dos en un polígono simple P, (MAXIMUN HIDDEN VERTEX SET) es un problema NP-duro [6]. En este trabajo se resuelve el problema para dos tipos de polígonos: espirales e histogramas. Para los primeros se obtiene un algoritmo lineal que resuelve el problema MHVS y cotas para el máximo número h de vértices ocultos, [r2 ]+ 1 ≤ h ≤ r + 1, siendo r el número de vértices cóncavos del polígono espiral. Para polígonos histograma se demuestra que h = r − (p − 1), siendo p el número de lados fondo