22,307 research outputs found
Are all the frames equally important?
In this work, we address the problem of measuring and predicting temporal
video saliency - a metric which defines the importance of a video frame for
human attention. Unlike the conventional spatial saliency which defines the
location of the salient regions within a frame (as it is done for still
images), temporal saliency considers importance of a frame as a whole and may
not exist apart from context. The proposed interface is an interactive
cursor-based algorithm for collecting experimental data about temporal
saliency. We collect the first human responses and perform their analysis. As a
result, we show that qualitatively, the produced scores have very explicit
meaning of the semantic changes in a frame, while quantitatively being highly
correlated between all the observers. Apart from that, we show that the
proposed tool can simultaneously collect fixations similar to the ones produced
by eye-tracker in a more affordable way. Further, this approach may be used for
creation of first temporal saliency datasets which will allow training
computational predictive algorithms. The proposed interface does not rely on
any special equipment, which allows to run it remotely and cover a wide
audience.Comment: CHI'20 Late Breaking Work
Action Recognition in Videos: from Motion Capture Labs to the Web
This paper presents a survey of human action recognition approaches based on
visual data recorded from a single video camera. We propose an organizing
framework which puts in evidence the evolution of the area, with techniques
moving from heavily constrained motion capture scenarios towards more
challenging, realistic, "in the wild" videos. The proposed organization is
based on the representation used as input for the recognition task, emphasizing
the hypothesis assumed and thus, the constraints imposed on the type of video
that each technique is able to address. Expliciting the hypothesis and
constraints makes the framework particularly useful to select a method, given
an application. Another advantage of the proposed organization is that it
allows categorizing newest approaches seamlessly with traditional ones, while
providing an insightful perspective of the evolution of the action recognition
task up to now. That perspective is the basis for the discussion in the end of
the paper, where we also present the main open issues in the area.Comment: Preprint submitted to CVIU, survey paper, 46 pages, 2 figures, 4
table
Vision-Based Production of Personalized Video
In this paper we present a novel vision-based system for the automated production of personalised video souvenirs for visitors in leisure and cultural heritage venues. Visitors are visually identified and tracked through a camera network. The system produces a personalized DVD souvenir at the end of a visitor’s stay allowing visitors to relive their experiences. We analyze how we identify visitors by fusing facial and body features, how we track visitors, how the tracker recovers from failures due to occlusions, as well as how we annotate and compile the final product. Our experiments demonstrate the feasibility of the proposed approach
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