Video Mapping Research Articles

A biomimetic underwater microrobot with multifunctional locomotion

Underwater microrobots are in urgent demand for applications such as pollution detection and video mapping in limited space. Compact structure, multi-functionality, and flexibility are normally considered incompatible characteristics for underwater microrobots. Nevertheless, to accomplish our objectives, we designed a novel inchworm-inspired biomimetic locomotion prototype with ionic polymer metal composite (IPMC) actuators, and conducted experiments to evaluate its crawling speed on a flat underwater surface. Based on this type of biomimetic locomotion, we introduced a new type of underwater microrobot, using ten IPMC actuators as legs or fingers to implement walking, rotating, floating, and grasping motions. We analysed the walking mechanism of the microrobot and calculated its theoretical walking speed. We then constructed a prototype of the microrobot, and carried out a series of experiments to evaluate its walking and floating speeds. Diving/surfacing experiments were also performed by electrolysing the water around the surfaces of the actuators. The microrobot used six of its actuators to grasp small objects while walking or floating. To implement closed-loop control, we employed three proximity sensors on the microrobot to detect an object or avoid an obstacle while walking.

Rapid Characterization of Shorelines Using a Georeferenced Video Mapping System

Abstract Anderson, M.G.; Judd, C., and Marcoe, K., 2012. Rapid characterization of shorelines using a georeferenced video mapping system. Mapping shoreline resources is crucial for coastal planning, yet current approaches are limited in ability to characterize remote areas or detect small features. Documentation using video mapping may provide a rapid and repeatable method for assessing the current state of the environment and determining changes to the shoreline over time. In this publication, we compare two studies using boat-based, georeferenced video mapping in coastal Washington and the Columbia River Estuary to map and characterize coastal stressors and shoreline condition. The coastal Washington study in Clallam County was completed in 1 day and covered a distance of 70 km, whereas the Columbia River Estuary study was conducted over a 10-day period and covered 1030 km. In both areas, multiple features were mapped along the shoreline. The position and orientation of the camera allowed for characteri...

An Online Spectral Learning Algorithm for Partially Observable Nonlinear Dynamical Systems

Recently, a number of researchers have proposed spectral algorithms for learning models of dynamical systems — for example, Hidden Markov Models (HMMs), Partially Observable Markov Decision Processes (POMDPs), and Transformed Predictive State Representations (TPSRs). These algorithms are attractive since they are statistically consistent and not subject to local optima. However, they are batch methods: they need to store their entire training data set in memory at once and operate on it as a large matrix, and so they cannot scale to extremely large data sets (either many examples or many features per example). In turn, this restriction limits their ability to learn accurate models of complex systems. To overcome these limitations, we propose a new online spectral algorithm, which uses tricks such as incremental Singular Value Decomposition (SVD) and random projections to scale to much larger data sets and more complex systems than previous methods. We demonstrate the new method on an inertial measurement prediction task and a high-bandwidth video mapping task and we illustrate desirable behaviors such as "closing the loop," where the latent state representation changes suddenly as the learner recognizes that it has returned to a previously known place.

A VIDEO PROJECTION MAPPING CONCEPTUAL DESIGN AND APPLICATION: YEKPARE

Can recent developments in video projection techniques aid us in finding new ways of expressing our creativity and creative audio-visual works on a new surface other than the screen? Video Mapping is one of the newest video projection techniques that are used to turn almost any surface into a dynamic video display. The aim of video mapping is to create a physical illusion of images by combining audio-visual elements. Most of the mapping projects are used in fashion shows, corporate events, concerts and theatrical performances. Lately a new trend of video mapping system is being used on architectural and historical structures, buildings and displayed in public spaces to reach a wider audience. This paper will focus on 3 aspects of video mapping and its application; 1) the technical aspects of video mapping and its tools. 2) the conceptual development of the project YEKPARE and the application of video mapping on Haydarpasa Terminal within the Istanbul 2010 European Capital of Culture events. 3) the feedback from the audiences who have experienced the performance and the effects of video mapping.

A fibre optic catheter for simultaneous measurement of longitudinal and circumferential muscular activity in the gastrointestinal tract

Diagnostic catheters based on fibre Bragg gratings (FBG's) are proving to be highly effective for measurement of the muscular activity associated with motility in the human gut. While the primary muscular contractions that generate peristalsis are circumferential in nature, it has long been known that there is also a component of longitudinal contractility present, acting in harmony with the circumferential component to improve the overall efficiency of material movement. We report the detection of longitudinal motion in mammalian intestine using an FBG technique that should be viable for similar detection in humans. The longitudinal sensors have been combined with our previously reported FBG pressure sensing elements to form a composite catheter that allows the relative phase between the two components to be detected. The catheter output has been validated using video mapping in an ex-vivo rabbit ileum preparation.

Temporal relationships between wall motion, intraluminal pressure, and flow in the isolated rabbit small intestine

Intraluminal manometry is a tool commonly used to record motility in the human digestive tract. The recorded signal results from a combination of factors, including the hydrodynamic pressure transmitted through the intestinal contents due to contraction of the gut wall and the force of the gut wall acting on the sensors in regions of a luminal occlusion. However, the actual relationships between small bowel wall contraction, the measured intraluminal pressure, and the resultant flow have not been directly addressed. Video recording and high-resolution fiber-optic manometry were used to create spatiotemporal video maps of diameter and intraluminal pressure from isolated segments of rabbit small intestine. In the unstimulated gut, longitudinal muscle contractions were the only detectable motor pattern; circular muscle contractions were elicited by distension or erythromycin (1 μM). Longitudinal muscle contractions were not lumen-occlusive, although they caused measurable low-amplitude changes in pressure. Localized nonpropagating circular muscle contractions caused small localized, nonpropagating peaks of intraluminal pressure. Propagating contractions of circular muscle evoked larger, propagating pressure changes that were associated with outflow. Propagating circular muscle contractions often caused dilation of aboral receiving segments, corresponding to "common cavities"; these were propulsive, despite their low intraluminal pressure. The highest-amplitude pressure events were caused by lumen-occlusive circular muscle contractions that squeezed directly against the catheter. These data allow us to define the complex relationships between wall motion, intraluminal pressure, and flow. A strong correlation between circular and longitudinal muscle contraction and intraluminal pressure was demonstrated. Common-cavity pressure events, caused by propulsion of content by circular muscle contractions into a receptive segment, were often of low amplitude but were highly propulsive. Studies of wall motion in isolated preparations, combined with manometry, can assist in interpretation of pressure recordings in vivo.

Mobile mapping technology of wind velocity data along highway for traffic safety evaluation

Traffic safety of highway vehicles under strong crosswind gust and other hazardous driving conditions has become a pressing issue for modern highway transportation and economy. It is known that the actual wind environment at the typical height of a moving vehicle varies considerably from one segment to another even on the same highway, because of influence of the specific terrain and surroundings. Therefore, accurate crosswind velocity data in both time and spatial domains are needed, for a rational assessment of traffic safety risks for various moving vehicles on highways in windy conditions. In addition to site-specific wind data which can be used for most vehicles, vehicle-specific crosswind velocity is often required for an accurate safety assessment of high-sided vehicles with unique shapes. A mobile mapping technology aiming at collecting site-specific as well as vehicle-specific wind velocity data for traffic safety evaluations was developed. Such technology integrates a 3D sonic anemometer and geospatial video mapping system, mounted on a vehicle driven along highways at a normal (cruising) speed. As a result, both vehicle-specific and general site-specific crosswind velocity can be directly “sensed” and collected by using a high-sided vehicle or a streamlined car as the test vehicle. A field test of the developed technology with a high-sided truck driven on mountainous sections of the interstate I-70 (in Colorado) was conducted. The crosswind data at six selected feature locations along I-70, representing different roadside environments, was analyzed. Wind-tunnel investigations employing the scaled models of the truck used in the field test as well as a common streamlined sedan car were conducted to evaluate the accuracy and the feasibility of the developed technology.

High-quality brightness enhancement functions for real-time reverse tone mapping

This paper presents an automatic technique for producing high-quality brightness-enhancement functions for real-time reverse tone mapping of images and videos. Our approach uses a bilateral filter to obtain smooth results while preserving sharp luminance discontinuities, and can be efficiently implemented on GPUs. We demonstrate the effectiveness of our approach by reverse tone mapping several images and videos. Experiments based on HDR visible difference predicator and on an image distortion metric indicate that the results produced by our method are less prone to visible artifacts than the ones obtained with the state-of-the-art technique for real-time automatic computation of brightness enhancement functions.

On the helical flow of Langmuir circulation — Approaching the process of suspension freezing

A series of tank experiments in non-freezing and freezing conditions was conducted to determine the development of Langmuir circulation (Lc) and to investigate how Lc may enhance the process of suspension freezing (incorporation of suspended sediment into newly formed ice). In non-freezing tank experiments, paired, counter rotating Lc cells were outlined by streaks of KMnO4 dye at bottom convergence zones, and by lines of positively buoyant particles at surface convergences. In freezing experiments, Lc was visualized by bottom KMnO4 and sediment streaks, and by surface windrows of frazil crystals. our results demonstrate the complex helical flow of microscale Langmuir trajectories using individual frazil crystals and KMnO4 dye striations as Lagrangian tracers visualized by photos and digital video mapping. Though individual helical Lc trajectories in our tank experiments are temporary and short-lived, we conclude that the development of bottom streaks, and the continuous rotary motion of frazil and KMnO4 dye striations indicate a permanent helical flow. A conceptual model bolstered by dimensional analysis of frazil and suspended sediment motion demonstrates the potential of Lc driving the interaction between frazil ice and sediment in the water column. The amount of sediment entrained into newly formed ice in our experiments exceeded the suspended particle concentration of tank water by a factor of >2. From our results we conjecture potential for Lc-induced sediment entrainment into grease ice in natural freezing waters. (C) 2008 Elsevier B.V. All rights reserved.

RAPID ASSESSMENT PROTOCOLS FOR SMALL VESSEL GROUNDINGS

ABSTRACT Vessel groundings in coral or seagrass habitats can cause significant injury to these benthic communities. Injury assessment requires information on the areal extent and degrees of injury at the grounding site, including the inbound and exit vessel tracks. Scientific divers need to rapidly delineate the boundaries of the impacted areas, map the location of specific points (such as large dislodged coral heads), and record observations along transects underwater. A series of 2–3 page protocols was developed to provide guidance on collection of key ephemeral data after small vessel groundings, particularly where resources are limited and access is difficult. The Initial Assessment protocol outlines the steps to plan and conduct emergency phase surveys to document the physical injuries. Guidance is provided on how to set up the sampling grids, develop site-specific injury categories, and record field parameters. The Live Coral Triage protocol describes how to salvage and stabilize live coral and associated resources in a coral reef or hardbottom habitat that have been physically fractured, dislodged, or overturned. The Underwater Video Mapping protocol describes how to document and provide a permanent video record of the area, type, and degree of physical damage to benthic communities. These protocols for small vessel groundings should assist first responders collect ephemeral data during the emergency phases of a response and start the recovery process.

Nearshore Substrate and Morphology Offshore of the Elwha River, Washington

The planned removal of two dams on the Elwha River, Washington, will likely increase river sediment flux to the coast, which may alter coastal habitats through sedimentation and turbidity. It is therefore important to characterize the current habitat conditions near the river mouth, so that future changes can be identified. Here we provide combined sonar and video mapping results of approximately 20 km2 of seafloor offshore of the Elwha River collected with the purpose to characterize nearshore substrate type and distribution prior to dam removal. These combined data suggest that the nearshore of the western delta and Freshwater Bay are dominated by coarse sediment (sand, gravel, cobble, and boulders) and bedrock outcrops; no fine-grained sediment (mud or silt) was identified within the survey limits. The substrate is generally coarser in Freshwater Bay and on the western flank of the delta, where boulders and bedrock outcrops occur, than directly offshore and east of the river mouth. High variation in substrate was observed within much of the study area, however, and distinct boulder fields, gravel beds and sand waves were observed with spatial scales of 10–100 m. Gravel beds and sand waves suggest that sediment transport is active in the study area, presumably in response to tidal currents and waves. Both historic (1912) and recent (1989–2004) distributions of Bull Kelp (Nereocystis sp.) beds were preferentially located along the boulder and bedrock substrates of Freshwater Bay. Although kelp has also been mapped in areas dominated by gravel and sand substrate, it typically has smaller canopy areas and lower temporal persistence in these regions.

POTENTIAL FOR REMOTE SENSING FROM AGRICULTURAL AIRCRAFT USING DIGITAL VIDEO

A field imaging system using low-cost digital video was evaluated for use on agricultural aircraft. The system usesa digital video (DV) camera, Global Positioning System (GPS), and Video Mapping System (VMS) for image georeferencing.Remote control and monitoring was implemented to allow the pilot to image specific field areas of interest, facilitating imageacquisition and post-processing. Two practical applications are described to exemplify the use of digital video in agriculturalaircraft. Broadleaf weeds were distinguished from cotton, and chlorophyll a (chl a) concentration was regressed againstdigital numbers obtained from images of catfish ponds. For the weed detection study, a mixture of spotted spurge (Euphorbiamaculata L.) and hyssop spurge (Euphorbia hyssopifolia L.) were distinguishable from both early cotton (Gossypiumhirsutum L.) and Johnsongrass (Sorghum halepense (L.) Pers.) using supervised classification algorithms. Results comparinga Mahalanobis Distance-classified image with the raw RGB image indicated cotton, spurge, and Johnsongrass correctlyclassified with 73%, 67%, and 82% accuracy, respectively. For the pond study, statistically significant relationships wereobserved between digital numbers from pond images and chlorophyll a (chl a ) from water samples obtained at multiple ponds.These experiments demonstrate the potential benefits of using low-cost digital video on aircraft to assist agriculturalproducers in improving management decisions.

The Effects of Modern Navagation on Driver Distraction

This study simulated modern in car navigation with video mapping cues and a low fidelity driving simulator. Forty one participants performed a simulated driving task while either free driving or navigating in conjunction with a standard additional task assessing their spare attentional capacity. The results showed that more lane deviations were made during the navigation than the non navigation task. These findings indicate the greater workload levels associated with the use of video navigation devices. These findings have major implications for driver safety and telematic systems design.

IMPROVING BANDWIDTH EFFICIENCY IN DISTRIBUTED VIDEO-ON-DEMAND ARCHITECTURES

Distributed Video-on-Demand (DVoD) systems are proposed as a solution to the limited streaming capacity and null scalability of centralized systems. In a previous work, we proposed a fully distributed large-scale VoD architecture, called Double P-Tree, which has shown itself to be a good approach to the design of flexible and scalable DVoD systems. In this paper, we present relevant design aspects related to video mapping and traffic balancing in order to improve Double P-Tree architecture performance. Our simulation results demonstrate that these techniques yield a more efficient system and considerably increase its streaming capacity. The results also show the crucial importance of topology connectivity in improving multicasting performance in DVoD systems. Finally, a comparison among several DVoD architectures was performed using simulation, and the results show that the Double P-Tree architecture incorporating mapping and load balancing policies outperforms similar DVoD architectures.

Research on sunspot Oscillations – I. The Pulkovo CCD Spectroheliograph-Magnetograph

The CCD spectroheliograph-magnetograph is a focal-plane ancillary instrument for the Pulkovo horizontal solar telescope ACU-5. The instrument is placed at an exit port of an isothermal high-resolution diffraction-grating spectrograph. A modified Leighton optical scheme for registration of sunspot magnetic fields is used. The instrument provides FITS-format digital video maps of radial velocities, magnetic fields, and spectroheliograms in any line of the spectral region 3900–11000 A. The time to obtain one video map of size 91′′×154′′ is equal to 10.24 s. The angular resolution of the instrument is 0.8′′; spectral resolution is 0.01–0.03 A. Since 1996 the Pulkovo CCD spectroheliograph-magnetograph has been used to obtain high spatial and temporal resolution observations of oscillations of radial velocities and magnetic fields in the photospheric layers of sunspots.

CONTINUOUS GEOREFERENCING FOR VIDEO–BASED REMOTE SENSING ON AGRICULTURAL AIRCRAFT

An imagebased remote sensing system was configured on an agricultural spray plane. The system uses a videomapping system (VMS) for continuous georeferencing of images obtained by digital video. Three differential GlobalPositioning System (GPS) configurations and one nondifferential system, dedicated to the imaging system, were evaluatedin parallel with the planes GPS to judge useable accuracy of a GPS/VMS combination when flying at altitudes of 21 to 420 m(70 to 1400 ft). Positioning accuracy was determined by comparing data from the GPS and video mapping system on theairplane to precise GPS data on the ground. One differential GPS configuration and the nondifferential GPS performed bestand had fewest problems updating a position fix. Over four field sections flown, differences in position ranged from 66 to+39 m (216 to +128 ft) using the differential GPS and from 11 to +83 m (36 to +272 ft) using the nondifferential GPSin separate tests. Differential correction was not necessary for reasonable accuracy within system limitations, but accuracywas frequently influenced by user subjectivity when locating points using the video mapping software. The system should findits greatest utility where field areas cannot be georeferenced using landmarks or other reference points, as would be the casefor lowaltitude remote sensing over large field areas.

A low-cost procedure for automatic seafloor mapping, with particular reference to coral reef conservation in developing nations

Loss of marine biodiversity through benthic habitat destruction has created urgent needs for low-cost, high-performance seafloor survey methods. However, accurate seafloor mapping and classification is usually an expensive undertaking requiring sophisticated equipment, which excludes important low-budget user groups in developing nations. In this paper, we introduce a low-cost procedure for seafloor mapping based on free-of-charge data acquisition software that can be downloaded from the Internet. Using a Malaysian coral-reef case-study, we show how comprehensive bathymetric mapping can be implemented with such software using inexpensive eccosounder and GPS, and describe principles for integration of environmental data, either by connecting additional instruments to the computer (up to 32 instruments with up to eight channels each can be handled simultaneously), or by using simple synchronisation techniques with equipment that records to separate media, such as video cameras. We mapped a Malaysian coral-reef area of 114 hectares in 6 hours of video mapping, achieving reef mapping rates that matches rates currently achieved only with air-borne imaging devices. However, the present methodology results in completely ground-truthed data that can be classified according to many schemes by direct observation of the habitat, and provides detailed bathymetric data that satellite imagery or air-borne spectrographic sensors do not provide. The method can be used as a stand-alone reef mapping and classification tool on the scale of tens to hundreds of square kilometres. On larger scales (thousands of square kilometres), airborne survey methods are likely to remain more cost-effective than boat-based methods, yet also in such settings this simple method offer unprecedented capacity for ground truthing and thereby increased capacity for habitat classification.

Preparation of Intramural Small Coronary Artery and Arteriole Segments and Resistance Artery Networks from the Rat Heart for Microarteriography and for in Situ Perfusion Video Mapping

Preparation of Intramural Small Coronary Artery and Arteriole Segments and Resistance Artery Networks from the Rat Heart for Microarteriography and for in Situ Perfusion Video Mapping

High-resolution optical mapping of the right bundle branch in connexin40 knockout mice reveals slow conduction in the specialized conduction system.

Connexin40 (Cx40) is a major gap junction protein that is expressed in the His-Purkinje system and thought to be a critical determinant of cell-to-cell communication and conduction of electrical impulses. Video maps of the ventricular epicardium and the proximal segment of the right bundle branch (RBB) were obtained using a high-speed CCD camera while simultaneously recording volume-conducted ECGs. In Cx40(-/-) mice, the PR interval was prolonged (47.4+/-1.4 in wild-type [WT] [n=6] and 57.5+/-2.8 in Cx40(-/-) [n=6]; P<0.01). WT ventricular epicardial activation was characterized by focused breakthroughs that originated first on the right ventricle (RV) and then the left ventricle (LV). In Cx40(-/-) hearts, the RV breakthrough occurred after the LV breakthrough. Additionally, Cx40(-/-) mice showed RV breakthrough times that were significantly delayed with respect to QRS complex onset (3.7+/-0.7 ms in WT [n=6] and 6.5+/-0.7 ms in Cx40(-/-) [n=6]; P<0.01), whereas LV breakthrough times did not change. Conduction velocity measurements from optical mapping of the RBB revealed slow conduction in Cx40(-/-) mice (74.5+/-3 cm/s in WT [n=7] and 43.7+/-6 cm/s in Cx40(-/-) [n=7]; P<0.01). In addition, simultaneous ECG records demonstrated significant delays in Cx40(-/-) RBB activation time with respect to P time (P-RBB time; 41.6+/-1.9 ms in WT [n=7] and 55.1+/-1.3 ms in [n=7]; P<0.01). These data represent the first direct demonstration of conduction defects in the specialized conduction system of Cx40(-/-) mice and provide new insight into the role of gap junctions in cardiac impulse propagation.

Using New Video Mapping Technology in Landscape Ecology

iological and ecological monitoring continues to play an imp ortant role in the conservation of s pec i e s , n a tu ral com mu n i ti e s , and landscape s (Spellerberg 1991). Although resource-monitoring programs have advanced knowledge about natural ecosystems, weaknesses persist in our ability to rapidly t ransfer landscape-scale information to the public.Ecologists continue to search for new technologies to address this p roblem and to c ommunicate natural resource inf ormation quickly and effectively. New vid eo mapping technology may provide much-needed help. Ecologists realize that only a small portion of large nature reserves can be monit ored b ecause of cost and logistical constraints. However, plant and animal populations are usually pat chily distributed in sub populations scattered throughout heterogeneous landscapes, and they are often associated with rare habitats. These subpopulations and rare habitats may respond differently to climate change, land use, and management practices such as grazing, fire suppression, prescribed burning , or in vasion of exotic species (Stohlgren et al. 1997b). In many national parks, monuments, and wildlife reserves, a few long-term monitoring plots are used to infer the status and trends of natural resources in much larger areas. To make defensible inferences about populations, habitats, and landscapes, it is ne cessary to ext rapolate from a few monit oring plots (local scale) to the larger, unsampled landscape with known levels of accuracy and precision. Recent tech n o l ogical devel opm ents have given pop u l ati on bi o l ogists and landscape eco l ogists a unique tool for bri d ging the data gap bet ween small , i n ten s ively sampled m on i toring plots and the gre a ter landscape and for tra n sferring this inform a ti on qu i ck ly to re s o u rce managers and the publ i c . In this arti cl e , we bri ef ly de s c ri be this too l , a h a n d - h eld vi deo mapping sys tem linked to a geogra ph i c i n form a ti on sys tem (GIS). We provi de examples of its use in qu a n ti f ying patterns of n a tive and exo tic plant spec i e s and cryptobi o tic crusts in the new Grand Stairc a s e ‐ E s c a l a n te Na ti onal Monu m en t , Ut a h , and in su rveying aspen cl ones and regen era ti on in Rocky Mountain Na ti onal Pa rk , Co l orado. Te ch n ol ogical adva n ce s Video mapping links spatially explicit videos with a GIS. The c ombination o f videography, global positioning system (GPS),and field data would allow for rapid evaluation of monitoring data and visual field conditions by local and remote scientists and the public. Video mapping has not been portable. One video mapping system cur rently used by the USDA Forest Service was designed to map insect ou tbreaks from a small, lowflying airplane. The system emplo ys a full-sized vid eo