Real-time rendering of aerial perspective effect based on turbidity estimation

Abstract

In real outdoor scenes, objects distant from the observer suffer from a natural effect called aerial perspective that fades the colors of the objects and blends them to the environmental light color. The aerial perspective can be modeled using a physics-based approach; however, handling with the changing and unpredictable environmental illumination as well as the weather conditions of real scenes is challenging in terms of visual coherence and computational cost. In those cases, even state-of-the-art models fail to generate realistic synthesized aerial perspective effects. To overcome this limitation, we propose a real-time, turbidity-based, full-spectrum aerial perspective rendering approach. First, we estimate the atmospheric turbidity by matching luminance distributions of a captured sky image to sky models. The obtained turbidity is then employed for aerial perspective rendering using an improved scattering model. We performed a set of experiments to evaluate the scattering model and the aerial perspective model. We also provide a framework for real-time aerial perspective rendering. The results confirm that the proposed approach synthesizes realistic aerial perspective effects with low computational cost, outperforming state-of-the-art aerial perspective rendering methods for real scenes.