The active shape model is one of the important method in the field of the deformable models. In the fields of the medical image analysis and machine vision

it is an ever-increasingly broad application method. During the process of image fitting

however

distortions and displacements often happen if the target is not clear or the initial position of the model is not ideal

and there is a lack of effective correction strategies. In this paper

we firstly propose an active detection and correction based on the boundary moment invariants. By introducing the boundary moment invariants

the changes of the model can be quantification

and can be detected and corrected according to the statistical information which is obtained from the training set. Using the proposed method

distortions are effectively avoided and the accuracy of fitting result is obviously increased with little extra time. Finally

the results of our practical implementation prove that the proposed strategy works satisfactorily.