115,159 research outputs found
DECam integration tests on telescope simulator
The Dark Energy Survey (DES) is a next generation optical survey aimed at
measuring the expansion history of the universe using four probes: weak
gravitational lensing, galaxy cluster counts, baryon acoustic oscillations, and
Type Ia supernovae. To perform the survey, the DES Collaboration is building
the Dark Energy Camera (DECam), a 3 square degree, 570 Megapixel CCD camera
which will be mounted at the Blanco 4-meter telescope at the Cerro Tololo
Inter- American Observatory. DES will survey 5000 square degrees of the
southern galactic cap in 5 filters (g, r, i, z, Y). DECam will be comprised of
74 250 micron thick fully depleted CCDs: 62 2k x 4k CCDs for imaging and 12 2k
x 2k CCDs for guiding and focus. Construction of DECam is nearing completion.
In order to verify that the camera meets technical specifications for DES and
to reduce the time required to commission the instrument, we have constructed a
full sized telescope simulator and performed full system testing and
integration prior to shipping. To complete this comprehensive test phase we
have simulated a DES observing run in which we have collected 4 nights worth of
data. We report on the results of these unique tests performed for the DECam
and its impact on the experiments progress.Comment: Proceedings of the 2nd International Conference on Technology and
Instrumentation in Particle Physics (TIPP 2011). To appear in Physics
Procedia. 8 pages, 3 figure
Ambient Multi-Camera Personal Documentary
Polymnia is an automated solution for the creation of ambient multi-camera personal documentary films. This short paper introduces the system, emphasising the rule-based documentary generation engine that we have created to assemble an edited narrative from source footage. We describe how such automatically generated media can be integrated with and augment personally-authored images and videos as a contribution to an individual’s personal digital memory
Evaluation campaigns and TRECVid
The TREC Video Retrieval Evaluation (TRECVid) is an
international benchmarking activity to encourage research
in video information retrieval by providing a large test collection, uniform scoring procedures, and a forum for organizations interested in comparing their results. TRECVid completed its fifth annual cycle at the end of 2005 and in 2006 TRECVid will involve almost 70 research organizations, universities and other consortia. Throughout its existence, TRECVid has benchmarked both interactive and automatic/manual searching for shots from within a video
corpus, automatic detection of a variety of semantic and
low-level video features, shot boundary detection and the
detection of story boundaries in broadcast TV news. This
paper will give an introduction to information retrieval (IR) evaluation from both a user and a system perspective, highlighting that system evaluation is by far the most prevalent type of evaluation carried out. We also include a summary of TRECVid as an example of a system evaluation benchmarking campaign and this allows us to discuss whether
such campaigns are a good thing or a bad thing. There are
arguments for and against these campaigns and we present
some of them in the paper concluding that on balance they
have had a very positive impact on research progress
Multimedia information technology and the annotation of video
The state of the art in multimedia information technology has not progressed to the point where a single solution is available to meet all reasonable needs of documentalists and users of video archives. In general, we do not have an optimistic view of the usability of new technology in this domain, but digitization and digital power can be expected to cause a small revolution in the area of video archiving. The volume of data leads to two views of the future: on the pessimistic side, overload of data will cause lack of annotation capacity, and on the optimistic side, there will be enough data from which to learn selected concepts that can be deployed to support automatic annotation. At the threshold of this interesting era, we make an attempt to describe the state of the art in technology. We sample the progress in text, sound, and image processing, as well as in machine learning
Polaroid after digital: technology, cultural form, and the social practices of snapshot photography
The essay is part of a larger project on the cultural history of Polaroid photography and draws on research done at the Polaroid Corporate archive at Harvard and at the Polaroid company itself in Waltham and Concord Massachusetts. It sets out to make an addition to the understanding of the new social practices generated by digital photography, but does so by examining an old technology rendered obsolete by the new. It outlines the recent history and decline of Polaroid and identifies the specific properties of the Polaroid image: its speed of appearance, its elimination of the darkroom, and the singularity of the final print. It then addresses the significance of the affinities and differences between the old and new ‘instant’ photographies, particularly in terms of the snapshot practices that they encourage
Indexing, browsing and searching of digital video
Video is a communications medium that normally brings together moving pictures with a synchronised audio track into a discrete piece or pieces of information. The size of a “piece ” of video can variously be referred to as a frame, a shot, a scene, a clip, a programme or an episode, and these are distinguished by their lengths and by their composition. We shall return to the definition of each of these in section 4 this chapter. In modern society, video is ver
The city as a construction site — a visual record of a multisensory experience
In this article, I consider the reception of images that are present in a city space. I focus on the juxtaposition of computer‑generated images covering fences surrounding construction sites and the real spaces which they screen from view. I postulate that a visual experience is dependent on input from the other human senses. While looking at objects, we are not only standing in front of them but are being influenced by them. Seeing does not leave a physical trace on the object; instead the interference is more subtle — it influences the way in which we perceive space. Following in the footsteps of Sarah Pink, Michael Taussig and William J. T. Mitchell, I show that seeing (to paraphrase the title of an article by the last of the above mentioned scholars) is a cultural practice. The last part of the article presents a visual essay as a method that can contribute to cultural urban studies. I give as an example of such a method a photo‑essay about chosen construction sites in Poznań, which I photographed between December 2014 and June 2015
So what can we actually do with content-based video retrieval?
In this talk I will give a roller-coaster survey of the state of the art in automatic video analysis, indexing, summarisation, search and browsing as demonstrated in the annual TRECVid benchmarking evaluation campaign. I will concentrate on content-based techniques for video management which form a complement to the dominant paradigm of metadata or tag-based video management and I will use example techniques to illustrate these
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