Aiming at large amount of computation

a new method of 2-D object attitude measurement based on covariance matrix is presented. Firstly

binary the image and calculate the center of object. Then

compute covariance matrix of the object area. Finally

get the ellipse area defined by covariance matrix

and compute the length and orientation of both axes. The ratio of corresponding axes is the scale change

and the orientation difference of corresponding axes is the rotation angle. The experimental results show that the presented method can calculate the rotation and scale change fast and accurately

the angle error is within

and the scale error is within

while the computation time is 1/16 of that of log-polar method.