Random Coded Sampling for High-Speed HDR Video

Sampling Scheme

Travis Portz, Li Zhang, and Hongrui Jiang

University of Wisconsin, Madison

This paper proposes a random coded sampling method for capturing high-speed HDR videos. At each frame, we sample a subset of pixels with predefined random exposure times; other pixels that are not sampled at this frame continue to expose. For example, at frame a, pixels 1, 6, and 9 are read; at frame b (7 frames after frame a), pixels 3 and 7 are read. Color bars indicate exposure length. Our algorithm reconstructs full-frame high-speed HDR videos.

Advantages

Our exposure scheme has 4 advanatages:

Comparison to Alternative Schemes

We compare our sampling scheme with conventional global constant exposure settings that operate at a frame rate of 1/4 the high-speed frame rate; the factor 1/4 is used because with current parameters, our random sampling scheme has a compression ratio of 4:1. In particular, we use two constant exposure settings: a long exposure time that corresponds to 4 high-speed frames (referred to as 4x exposure in the following examples) and a short exposure time that corresponds to 1 high-speed frame (referred to as 1x exposure).

For further comparison of our results to the constant 1x exposure videos, we show denoising results of the 1x exposure videos using the CBM3D method. We did not use the video version of this method (CVBM3D) because its output is quantized, leading to poor results in dark regions after applying a curve adjustment.

Please install Flash Player and enable Javascript to view the videos in our supplementary material. We also provide links to view the videos externally.

Publication

``Random Coded Sampling for High-Speed HDR Video'', Travis Portz, Li Zhang, and Hongrui Jiang, International Conference on Computational Photograpy (ICCP), Boston, MA, April 2013. [PDF][PPT (with embedded videos, 20MB)][PDF (no videos, 1MB)]

Patent

Patent Pending, ``Video Generation with Temporally-Offset Sampling'', Li Zhang and Travis Portz, WARF reference P130162US01.

Videos

Additional Information