Chromatic adaptation for robust visual navigation

This paper analyzes the effects of the application of visual adaptation mechanisms on snapshot-based guidance methods. The guidance principle of the visual homing is proven to be a visual potential function with an equilibrium point located at the goal position. The presence of a potential function means that classical control theory principles based on the Lyapunov functions can be applied to assess the robustness of the navigation strategy. The Retinex algorithm, a blind chromatic equalization pre-filtering that performs color constancy with no a priori information about the illuminant, is proposed as an unsupervised visual adaptation mechanism. It increases the visual information similarity under changes in the illuminant, thus increasing the robustness of the visual guidance. Tests and comparisons are presented.