Non-uniform Illumination Video Enhancement Based on Zone System and Fusion

Abstract

In daily life, the acquisition of digital video will introduce non-uniform exposure due to the set of shooting equipment or scene illumination. Due to the low visibility, details are hidden and these videos usually fail to present visually pleasing browsing. Previous work typically relies on a single heuristic tone mapping curve to expand the dynamic range, which inevitably leads to uneven exposure. To solve this problem, we present a new video enhancement method based on zone system and image fusion. Given an input non-uniform illumination video, we first apply the zone system for exposure evaluation. We then remap each region using a series of tone mapping curves to generate multi-exposure regions which contain different exposed versions. Guided by some visual perception quality measures, we locate all the best exposed regions and then integrate them into a well-exposed video frame. Finally, in order to keep temporal consistency, we temporally propagate the zone regions from the former frame to the current frame. Experimental results have shown that the enhanced video exhibits uniform exposure, and preserves temporal consistency.