This paper presented a multi-scale light spot center location method to extract the center location for irregular light spots in an image fast and accurately. Firstly

the region of the light spot was segmented by morphology operation and thresholding to determine the size of the image with spots. Then

the Hessian matrix was computed in the multi-scale image space in the light spot region. The best scale was determined by a determination coefficient from the eigenvalue of Hessian matrix

and the pixel level center location was computed. Finally

the image intensity function around the spot center pixel location was approximated by second order Taylor expansion and the sub-pixel center location was computed by finding the maxima of the approximated intensity function. Both the synthetic and real experiments verify that the proposed method has higher location accuracy and stronger robust. In a real experiment

the error of the light spot center location is less than 0.1 pixel. The method proposed has been put into the practice of video measuring systems.