Abstract:Aiming at the ambiguity of measurement results caused by the operator adjusting the camera focal length according to experience in optical measurement, and solving the defect that the traditional camera focusing approaches could not applicable to speckle texture image, a camera automatic focusing algorithm for speckle texture image is proposed based on the entropy, moment of inertia and correlation of gray level co-occurrence matrix., which could assist the operator in adjusting the camera. The speckle texture images collected in different experimental environments verity that the proposed algorithm has the characteristics of unimodal and unbiased hardware, and has certain anti-noise ability. Compared with the traditional evaluation algorithm, the proposed algorithm has stronger pertinence and better applicability to the judgment of speckle texture image, and can provide guarantee for subsequent accurate measurement.