A model-based approach to camera’s auto exposure control

• This work formulates the auto exposure (AE) control problem as a root finding problem with a convex/concave model.
• The work solves the AE control problem by apply an iterative root finding algorithm to the convex/concave model.
• The proposed solution is robust, fast and stable even under hardware malfunction.
• The superiority of the proposed solution is approved mathematically and demonstrated experimentally.
• This work sheds lights on previous AE control solutions under one unified mathematical framework.

A fast and robust camera’s auto exposure (AE) technique is proposed in this work. It is achieved by modeling the luminance characteristics of the imaging sensor as a concave or convex function of a control parameter (e.g., exposure time or speed) and the optimal control parameter is computed using a modified secant algorithm with fast convergence. Furthermore, the proposed solution is able to adjust the control parameter automatically in the presence of erroneous exposure. Its superior performance is confirmed by experimental results.