Real-Time Auto-Focus System Design Based on Climbing Algorithm and its FPGA Implementation

In real-time imaging applications, the auto-focus algorithm and hardware structure must be adapted to the limited resources for fast and accurate real-time auto-focusing. In this paper, to obtain more precision, a new clarity evaluation function base on image's edge energy is proposed. Then, we present the corresponding FPGA hardware implementation which has simple structure. Additionally, utilizing the prior knowledge during the climbing process, a new climbing algorithm for the auto-focus which has the random start point is proposed. The experiment results show the proposed auto-focus algorithm can reduce the steps during the climbing and accelerate the auto-focus speed simultaneously.