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Tunnel Brightness Compensation With Spatial–Temporal Visual-Content Preservation

Tunnels cause many traffic accidents in China every year, which is related to the inappropriate driving behaviors combined with less visual comfortability when driving across tunnels. The most common phenomenon when driving across the inlet and outlet sections of a tunnel is the abruptly varying visual brightness, causing a short-term blindness for a driver, known as the “black hole” and “white hole” effects, respectively. In this paper, we propose a tunnel brightness compensation model with spatial–temporal visual-content preservation. The highlights of this paper are twofold. 1) We analyze the visual brightness variation by introducing spatio-temporal orientation energy for a stable characterization of the visual comfortability of drivers in view of the distinguishable visual content caused by a sequential brightness variation. 2) We construct a tunnel brightness compensation model that preserves the spatial–temporal visual content by visual-content matching with multiple frames. Our method can manifestly improve the brightness quality and maintain the scene content simultaneously. Extensive visual brightness compensation experiments on 60 visual clips of inlet and outlet sections of tunnels demonstrate that the proposed method generates a state-of-the-art performance.