Inexpensive Video Cameras Research Articles

Digital Curation and Contemporary Documentary Filmmaking

AbstractDocumentary films have evolved considerably since 1922s Nanook of the North. Fans of nonfiction now stream multi-episode documentaries on platforms like Netflix or catch a feature at one of many documentary-centered film festivals around the world. Inexpensive video cameras and internet distribution have expanded the documentary film universe exponentially. From 1-min films to feature-length theater releases, moviegoers around the world have embraced this diverse and growing genre. To the benefit of aspiring filmmakers, documentaries can now be filmed on a wide array of digital video devices, including smartphones, and edited inexpensively. Given this abundance, it may seem counterintuitive that, from a preservation perspective, the documentary film genre faces substantial risks. Research indicates that independent filmmakers lack access to resources that would ensure the long-term stewardship of their works (Academy of Motion Picture Arts and Sciences 2012). This research project examines documentary film production through the lens of digital curation. It describes filmmakers’ data practices and proposes a data curation model designed to guide filmmakers and film archives in developing data management plans similar to those currently used by researchers in the sciences. The proposed data curation model reflects the influence of the growing research data management field and integrates components related to digital storage, copyright, publishing, context, and file organization.

Inferring Surface Flow Velocities in Sediment-Laden Alaskan Rivers from Optical Image Sequences Acquired from a Helicopter

The remote, inaccessible location of many rivers in Alaska creates a compelling need for remote sensing approaches to streamflow monitoring. Motivated by this objective, we evaluated the potential to infer flow velocities from optical image sequences acquired from a helicopter deployed above two large, sediment-laden rivers. Rather than artificial seeding, we used an ensemble correlation particle image velocimetry (PIV) algorithm to track the movement of boil vortices that upwell suspended sediment and produce a visible contrast at the water surface. This study introduced a general, modular workflow for image preparation (stabilization and geo-referencing), preprocessing (filtering and contrast enhancement), analysis (PIV), and postprocessing (scaling PIV output and assessing accuracy via comparison to field measurements). Applying this method to images acquired with a digital mapping camera and an inexpensive video camera highlighted the importance of image enhancement and the need to resample the data to an appropriate, coarser pixel size and a lower frame rate. We also developed a Parameter Optimization for PIV (POP) framework to guide selection of the interrogation area (IA) and frame rate for a particular application. POP results indicated that the performance of the PIV algorithm was highly robust and that relatively large IAs (64–320 pixels) and modest frame rates (0.5–2 Hz) yielded strong agreement ( R 2 > 0.9 ) between remotely sensed velocities and field measurements. Similarly, analysis of the sensitivity of PIV accuracy to image sequence duration showed that dwell times as short as 16 s would be sufficient at a frame rate of 1 Hz and could be cut in half if the frame rate were doubled. The results of this investigation indicate that helicopter-based remote sensing of velocities in sediment-laden rivers could contribute to noncontact streamgaging programs and enable reach-scale mapping of flow fields.

Monitoring the growth of III-nitride materials by plasma assisted molecular beam epitaxy employing diffuse scattering of RHEED

AlGaN alloys find important applications in UV emitters and detectors, as well as in high-power high-frequency electronics. While reflection high energy electron diffraction (RHEED) is a standard technique for in situ monitoring of the growth of AlGaN alloys by plasma assisted molecular beam epitaxy, this paper investigates a new mode of its application. During the growth of AlGaN alloys, the ratio of the group III (Al + Ga) to group V (active nitrogen) adatoms critically controls the materials property of AlGaN films and is optimal within a very narrow window of operation. Moreover, this ratio is dependent in a complex fashion on various growth parameters, including substrate temperature, and is difficult to determine quantitatively in real time. This paper provides a method to estimate that important parameter. This can be carried out through the capture of the RHEED image from the fluorescent screen using an inexpensive video camera setup and a simple analysis procedure. While most RHEED analyses focus on the diffraction pattern, e.g., the line spacing, this work quantifies diffused scattering of the electron beam from a metallic layer that forms on the top of the growth surface during deposition under excess group III conditions, which is typically employed during growth. Two alternate methods for data analysis have been explored and compared. The results indicate that this process can qualitatively trace the variation of the thickness of the thin metallic layer, and hence the group III to group V flux ratio, for different substrate temperatures. This technique being simple, fast, and cost-effective can be incorporated into standard MBE systems for real-time in situ characterization of AlGaN alloys.

Descriptor-based tracking algorithm using a depth camera

The appearance of inexpensive high-quality video cameras and depth cameras resulted in the development of a large number of object-tracking algorithms. In this paper, a new descriptor-based algorithm for real-time object tracking using the information from a Microsoft Kinect depth camera is proposed. As a descriptor for the object tracked, histograms of oriented gradients calculated from the circular sliding regions of the scene image are used. The information on the depth of the scene is used when the image of the object of interest is partially occluded by other objects in the scene. To speed up the tracking process, a model for predicting the object motion is used. To ensure real-time tracking with the proposed algorithm, a multicore graphics processor is used.

GbLN-PSO and Model-Based Particle Filter Approach for Tracking Human Movements in Large View Cases

Camera tracking systems have become a common requirement in today’s society. The availability of high-quality and inexpensive video cameras and the increasing need for automated video analysis have generated a great deal of interest in numerous fields.In general, it is not easy to track human behavior in an environment with a large view. This paper aims to address four problems associated with large view in camera tracking system: 1) multiple targets in nonlinear motion; 2) relative size of the targeted object; 3) occlusion; and 4) processing time. This paper presents a new method of tracking human movements using global best local neighborhood oriented particle swarm optimization and model-based particle filter to address the above problems. The proposed method has been tested with an experimental module using several sets of video data provided by the 11th IEEE International Workshop on Performance Evaluation of Tracking and Surveillance and two other video streams of University of British Columbia (UBC) hockey and Malaysian football games. The experiment has shown that the accuracy of tracking performance has increased up to 25% compared with other reported works in the scientific literature.

Positive Random Forest 기반의 강건한 객체 추적

고성능 컴퓨터와 디지털 카메라의 보급으로 컴퓨터를 이용한 객체 탐지 및 추적은 컴퓨터 비전의 다양한 응용분야에서 중요한 문제로 대두 되고 있다. 또한, 지능형 자동화 감시 장치, 영상 분석 장치, 자동화된 로봇 분야 등에서 그 필요성이 점점 부각 되고 있다. 객체 추적은 카메라를 이용하여 움직이는 객체의 위치를 찾는 처리 과정을 의미 하며, 강건한 객체 추적을 위해서는 객체의 스케일, 형태 변화, 회전에 강건하고 정확한 객체의 위치를 파악할 수 있어야한다. 본 논문에서는 랜덤 포레스트를 이용한 강건한 객체 추적에 대한 알고리즘을 제안하였다. 정확한 객체의 위치를 찾기 위해 지역 공분산과 ZNCC (Zeros Mean Normalized Cross Correlation)를 사용하여 객체를 검출하고 검출된 객체를 5개의 부분으로 나누어 랜덤 포레스트로 객체가 잘 검출 되었는지 검증 한다. 검증된 객체 중 모델을 선택하여 객체 검출이 잘못 되었다고 판단된 경우 입력 모델을 변경하여 정확한 객체를 찾도록 하였다. 제안된 알고리즘과 기존의 알고리즘들을 비교 하였을 때 비교적 정확한 객체의 위치를 잘 찾아 가는 것을 확인하였다.

What They Learned: Using Multimedia to Engage Undergraduates in Research

Today’s employers seek high levels of creativity, communication, and critical thinking, which are considered essential skills in the workplace. Engaging undergraduate students in critical thinking is especially challenging in introductory courses. The advent of YouTube, inexpensive video cameras, and easy-to-use video editors provides opportunities to increase students’ skill levels in these areas. In this article I explain the assignment of producing a public service announcement that integrates research, collaborative learning, and creativity into an introductory survey course; and I discuss the support necessary for students’ success. Their products demonstrate increased levels of media literacy, creativity, and critical thinking skills.

The Video Essay

The Video Essay Ned Stuckey-French (bio) In the winter of 1992, Phillip Lopate published a groundbreaking piece in the Threepenny Review titled "In Search of the Centaur: The Essay-Film." Lopate's attempt to define the essay elevated the form's words over its images. This centaur might be a hybrid, but it should "represent a single voice," possess a "strong, personal point of view," and be "eloquent, well-written and interesting." Lopate acknowledged the limitations of his approach and reminded readers he was a literary essayist and "not a film theorist," but his admissions did not stop film critics such as Paul Arthur, Laura Rascaroli, and Timothy Corrigan from criticizing Lopate's criteria as subjective and logocentric. Arthur pointed out, for instance, that because "film operates simultaneously on multiple discursive levels—image, speech, titles, music—the literary essay's single determining voice is dispersed into cinema's multi-channel stew." Lopate also fretted about how few essay-films there were. The form's rarity, he argued, resulted from film's collaborative nature and high production costs, and the medium's resistance to "verbal largesse" and tendency to catch and preserve unplanned images. These factors, he said, pulled the final cut away from the filmmaker's singular, essayistic vision. Of course, since 1992, when Lopate wrote, we've experienced a digital revolution. Lopate's essay-film is no longer rare, nor is it always as "literary" or word-centered as he thought it should be. Small, inexpensive video cameras, free editing software, and the Internet have made it easy to make and distribute videos. As John Bresland, one of a number of fine young video-essayists experimenting with this new technology, puts it, "Today, to make a small-scale personal film, you can shoot the thing on an inexpensive digital camera and upload it to any number of free video sharing sites.... You can shoot and edit video, compelling video, on a cell phone." Essay-films have become video essays, and they're everywhere. Facebook posts link to them. Online magazines devote special issues and regular sections to them. They've begun to appear in both literature and essay-writing classes. At universities such as Ohio State, Kentucky, Denver, and Florida State (where I teach), students are creating video essays in new, interdisciplinary programs that bring together editing, writing, rhetoric, and digital and media studies. High school students include video essays in their college applications. These popular, easy-to-use technologies allow millions of people, including many who consider themselves essayists first, to bypass production teams and wrestle individually with the problems Lopate raised. The results are exciting, but they are not usually feature-length films, though filmmakers that Lopate discussed such as Michael Moore and Ross McElwee have continued to produce important and longer work. Lopate (like most of the critics who have discussed the essay-film) did not address the question of length head-on. He wrote admiringly of the work of Chris Marker, for instance, but when he did, he did not talk about the question of length, even though Marker's work would seem to raise it. Lopate referred to the "essayistic tendency" in Marker's films Sans Soleil (1983) and Grin Without the Cat (1977), but did not mention the fact that the former is a hundred minutes long, the latter four hours. Video-essays today are more likely to be six minutes long, a length more in keeping with the print essay's tradition of brevity. Just as the Top 40 format of AM radio militated toward the two-minute single, so has YouTube led to the proliferation of the short video. Though video essays are available on YouTube, they are often collected first on the websites of video essayists or online magazines. If you are new to the form, a good place to start is the piece by John Bresland that I quoted above. Titled "On the Origin of the Video Essay," it introduced a suite of six video essays that Bresland curated for the spring 2010 issue of Blackbird magazine. In addition to Bresland's "Mangoes," a meditation on gender and fatherhood, the group includes pieces that use documentary montage, animation...

Simple gaze analysis and special design of a virtual Morris water maze provides a new method for differentiating egocentric and allocentric navigational strategy choice

We present a novel method of combining eye tracking with specially designed virtual environments to provide objective evidence of navigational strategy selection. A simple, inexpensive video camera with an easily built infrared LED array is used to capture eye movements at 60 Hz. Simple algorithms analyze gaze position at the start of each virtual maze trial to identify stimuli used for navigational orientation. To validate the methodology, human participants were tested in two virtual environments which differed with respect to features usable for navigation and which forced participants to use one or another of two well-known navigational strategies. Because the environmental features for the two kinds of navigation were clustered in different regions of the environment (and the video display), a simple analysis of gaze-position during the first (i.e., orienting) second of each trial revealed which features were being attended to, and therefore, which navigational strategy was about to be employed on the upcoming trial.

Eight Questions (and Answers) about Machinima

The author argues that, unlike traditional filmmaking or video recording through inexpensive digital videocameras, machinima presents a high barrier of entry, remaining a relatively complex method of creating videos. In fact, producing rendered animations generated from recordings of gameplay requires fairly high-end hardware capable of running real-time graphics intensive 3D or pseudo-3D environments. Nonetheless, machinima has the potential to make a real impact on the political landscape and can be considered a relatively sophisticated form of art, although one has to remember that art is socially constructed and it is not an intrinsic quality of an artifact.

Inexpensive video cameras used by parents to record social communication in epidemiological investigations in early childhood—A feasibility study

We tested the feasibility of parents recording social interactions with their infants using inexpensive camcorders, as a potential method of effective, convenient, and economical large scale data gathering on social communication. Participants were asked to record two short video clips during either play or a mealtime, and return the data. Sixty-five video clips (32 pairs) were returned by 33 families, comprising 8.5% of families contacted, 44.6% of respondents and 51.6% of those sent a camcorder, and the general visual and sound quality of the data was assessed.Audio and video quality were adequate for analysis in 85% of clips and several social behaviours, including social engagement and contingent responsiveness, could be assessed in 97% of clips. We examined two quantifiable social behaviours quantitatively in both adults and infants: gaze direction and duration, and vocalization occurrence and duration. It proved difficult for most observers to obtain a simultaneous clear view of the parents and infant's face.Video clips obtained by parents are informative and usable for analysis. Further work is required to establish the acceptability of this technique in longitudinal studies of child development and to maximize the return of usable data.

A simple, inexpensive video camera setup for the study of avian nest activity

Time-lapse video photography has become a valuable tool for collecting data on avian nest activity and depredation; however, commercially available systems are expensive (.USA $4000/unit). We designed an inexpensive system to identify causes of nest failure of American Oystercatchers (Haematopus palliatus) and assessed its utility at Cumberland Island National Seashore, Georgia. We successfully identified raccoon (Procyon lotor), bobcat (Lynx rufus), American Crow (Corvus brachyrhynchos), and ghost crab (Ocypode quadrata) predation on oystercatcher nests. Other detected causes of nest failure included tidal overwash, horse trampling, abandonment, and human destruction. System failure rates were comparable with commercially available units. Our system's efficacy and low cost ( ,$800) provided useful data for the management and conservation of the American Oys- tercatcher. SINOPSIS. Una camara sencilla y de bajo costo para observar la actividad en nidos La video fotografia por lapsos de tiempo se ha convertido en una herramienta muy valiosa para tomar datos de la actividad en nidos e identificar depredadores. Sin embargo, los equipos comerciales son costosos (.USA $4000/ unidad). Hemos disenado un equipo de bajo costo para identificar las causas de fracaso en la anidada del ostrero Haematopus palliatus ,yal a vez evaluar su utilidad. El estudio se llevoa cabo en Cumberland Island National Seashore, Georgia. Identificamos a Procyon lotor, Lynx rufus, Corvus brachyrhynchos ya Ocypode quadrata, como depredadores de los nidos de ostreros. Otros eventos que causaron el fracaso de la anida da lo fueron, el efectode mareas altas, pisadas de caballos y destruccion de los nidos por humanos. La tasa de mal funcionamiento del equipo que utilizamos fue comparable con la del equipo comerical. La eficacia de nuestro sistema y bajo costo ( ,$800) provee de datos utiles para la conservacion y manejo del ostrero.

The Webcam system: a simple, automated, computer-based video system for quantitative measurement of movement in nonhuman primates

Investigations using models of neurologic disease frequently involve quantifying animal motor activity. We developed a simple method for measuring motor activity using a computer-based video system (the Webcam system) consisting of an inexpensive video camera connected to a personal computer running customized software. Images of the animals are captured at half-second intervals and movement is quantified as the number of pixel changes between consecutive images. The Webcam system allows measurement of motor activity of the animals in their home cages, without devices affixed to their bodies. Webcam quantification of movement was validated by correlation with measures simultaneously obtained by two other methods: measurement of locomotion by interruption of infrared beams; and measurement of general motor activity using portable accelerometers. In untreated squirrel monkeys, correlations of Webcam and locomotor activity exceeded 0.79, and correlations with general activity counts exceeded 0.65. Webcam activity decreased after the monkeys were rendered parkinsonian by treatment with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), but the correlations with the other measures of motor activity were maintained. Webcam activity also correlated with clinical ratings of parkinsonism. These results indicate that the Webcam system is reliable under both untreated and experimental conditions and is an excellent method for quantifying motor activity in animals.

Low-cost video-films in the teaching of undergraduate and postgraduate medical students.

The high cost of producing good-quality video-films for teaching has hindered the use of this method, which has been shown to improve significantly the efficiency of teaching and the retention of knowledge. During the last five years, a series of short video-films has been produced using inexpensive video-cameras and home video-recording and editing equipment. A variety of techniques were developed to allow recording of lecture presentations, while using the equipment as a teaching aid, without the need for technical staff. The positioning of the camera, the monitor, the slide projector and lighting were critical to the productions. Similar productions at low cost were obtained from recordings of operating theatre sessions, tutorials and clinical ward rounds. A survey of students exposed to teaching with video-film as part of a lecture presentation confirmed that the subject matter being taught was more easily understood and enjoyable and generated more discussions on than other forms of teaching.

Real-time imaging of fluorescent flagellar filaments.

Bacteria swim by rotating flagellar filaments that are several micrometers long, but only about 20 nm in diameter. The filaments can exist in different polymorphic forms, having distinct values of curvature and twist. Rotation rates are on the order of 100 Hz. In the past, the motion of individual filaments has been visualized by dark-field or differential-interference-contrast microscopy, methods hampered by intense scattering from the cell body or shallow depth of field, respectively. We have found a simple procedure for fluorescently labeling cells and filaments that allows recording their motion in real time with an inexpensive video camera and an ordinary fluorescence microscope with mercury-arc or strobed laser illumination. We report our initial findings with cells of Escherichia coli. Tumbles (events that enable swimming cells to alter course) are remarkably varied. Not every filament on a cell needs to change its direction of rotation: different filaments can change directions at different times, and a tumble can result from the change in direction of only one. Polymorphic transformations tend to occur in the sequence normal, semicoiled, curly 1, with changes in the direction of movement of the cell body correlated with transformations to the semicoiled form.

Computer-based image analysis for the automated counting and morphological description of microalgae in culture

A largely unexplored area is the application of digital image processing to counting and sizing of microalgal cells from culture. Commercial systems are available, but have not been tested, nor necessarily optimized for high speed counting and sizing of phytoplankton. The present work describes the design, construction, specifications and comparative performance of an inexpensive system optimized for counting and sizing microalgal cells. This system has been tested with cells of the picoplankton to nanoplankton size ranges (1–20 μm). The hardware was a widely available standard microcomputer, an inexpensive video camera and monitor, and a video digitization board (frame grabber). A modifiable menu-driven program (PHYCOUNT) was written and provisions made to make this program available to other workers. The program is constructed such that it can be adapted to a variety of hardware setups Video digitization boards). Comparison of growth curves for microagae revealed there were no significant differences in division rate and cell yield as assessed by the image analysis method compared to manual counts with a hemacytometer. Several hundred cells were counted routinely within 10–15 s, far exceeding the counting rate achieved by hand tally. A variable transect feature allowed sampling every nth pixel and provided a substantial increase in execution speed. More than 1000 counts can be done per day. A protocol for the use of 96-well plates of polyvinyl chloride as counting chambers contributed to the processing of large numbers of samples rapidly. Other routines developed provided subtended area, defined the coordinates of cell perimeter, and derived cell length and width. The calculation of the latter two parameters was usually done off-line as data output is in standard numerical form accessible by other programs. Experience with daily use of the PHYCOUNT program and imaging hardware reveal that the system is reliable for cell counting and sizing. The presence of bacteria in the algal cultures does not affect cell counting or sizing.

A reciprocating apparatus for detecting ionizing rays

Investigations using models of neurologic disease frequently involve quantifying animal motor activity. We developed a simple method for measuring motor activity using a computer-based video system (the Webcam system) consisting of an inexpensive video camera connected to a personal computer running customized software. Images of the animals are captured at half-second intervals and movement is quantified as the number of pixel changes between consecutive images. The Webcam system allows measurement of motor activity of the animals in their home cages, without devices affixed to their bodies. Webcam quantification of movement was validated by correlation with measures simultaneously obtained by two other methods: measurement of locomotion by interruption of infrared beams; and measurement of general motor activity using portable accelerometers. In untreated squirrel monkeys, correlations of Webcam and locomotor activity exceeded 0.79, and correlations with general activity counts exceeded 0.65. Webcam activity decreased after the monkeys were rendered parkinsonian by treatment with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), but the correlations with the other measures of motor activity were maintained. Webcam activity also correlated with clinical ratings of parkinsonism. These results indicate that the Webcam system is reliable under both untreated and experimental conditions and is an excellent method for quantifying motor activity in animals.