Abstract：The concept of “effective area” is introduced in this paper based on detailed analysis of the problems of current active contour models: poor performance under interference

large computational cost

inability to converge to complex contours and difficulty of setting initial contour

etc. The above problems can be solved by setting the initial contour inside the so-called “effective area” and controlling the size of the “effective area”. Setting the initial contour inside the “effective area” is consistent with multi-scale edge detection methods based on wavelet transform. The size of “effective area” can be controlled by the number of GVF field iterations. Based on above discussion

a new contour initialization algorithm is implemented by connecting the initial points of different resolutions obtained using multi-scale edge detection methods based on wavelet transform and suitably controlling the number of GVF field iterations. Experiments show that the initial contour can be accurately set inside the “effective area” and the size of “effective area” can be reduced within 5 pixels from the true edges. The new contour initialization algorithm has also reduced computational cost and can perform reasonably well under interference.