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Computer Graphics Forum

ShutterApp: Spatio-temporal Exposure Control for Videos

Nestor Z. Salamon, Markus Billeter, and Elmar Eisemann

Left: single frame from 240Hz short-exposure video and a simulated long exposure at 30Hz by averaging 8 frames. Middle: Using the 240Hz input, our method enables mixing a long exposure in the periphery with a short exposure for the details on the pendulum. Via user annotations in the video, different shutter functions can be defined (top right). Annotations and shutter functions can be keyframed over time. Based on the annotations, our method defines an interpolated shutter function for each pixel (bottom right).

A camera’s shutter controls the incoming light that is reaching the camera sensor. Different shutters lead to wildly different results, and are often used as a tool in movies for artistic purpose, e.g., they can indirectly control the effect of motion blur. However, a physical camera is limited to a single shutter setting at any given moment. ShutterApp enables users to define spatio-temporally-varying virtual shutters that go beyond the options available in real-world camera systems. A user provides a sparse set of annotations that define shutter functions at selected locations in key frames. From this input, our solution defines shutter functions for each pixel of the video sequence using a suitable interpolation technique, which are then employed to derive the output video. Our solution performs in real-time on commodity hardware. Hereby, users can explore different options interactively, leading to a new level of expressiveness without having to rely on specialized hardware or laborious editing.

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Publisher Paper preprint

Citation

Nestor Z. Salamon, Markus Billeter, and Elmar Eisemann, ShutterApp: Spatio-temporal Exposure Control for Videos, Computer Graphics Forum, 38, pp. 675–683, 2019.

BibTex

@article{bib:salamon:2019,
    author       = { Salamon, Nestor Z. and Billeter, Markus and Eisemann, Elmar },    
    title        = { ShutterApp: Spatio-temporal Exposure Control for Videos },
    journal      = { Computer Graphics Forum },
    volume       = { 38 },
    year         = { 2019 },
    pages        = { 675--683 },
    doi          = { 10.1111/cgf.13870 },
    dblp         = { journals/cgf/SalamonBE19 },
    url          = { https://publications.graphics.tudelft.nl/papers/124 },
}