Auto-focus algorithm based on maximum gradient and threshold

Abstract

So as to conquer the disservices of the conventional auto-focus algorithm which are poor in real time performance, feeble in anti-noise capability and powerless against the impact of contrast and background pixels, here an auto-focus algorithm focused around greatest gradient and threshold is proposed. It presents an edge component and takes another sort of versatile threshold to evacuate the pixels sullied by noise and background in the picture, then uses enhanced Sobel operators to concentrate maximum gray gradient after picture pre processing and figures assessment esteem. The trial results demonstrate that the proposed algorithm has great continuous-execution, solid unimodality, high sensitivity and strong anti-noise capability. What's more, the algorithm is less impacted by contrast and background in the picture. It can additionally control the sensitivity and focusing reach of the focusing function. So the proposed algorithm is most suitable for auto focus