<html><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:12pt"><div>Hello,</div><div><br></div><div>I am using sigmoid filter in ITK to obtain an edge map of a 3D dicom volume. It works quite fine, but what confuses me is, it gives out an extra edge exactly in the middle of the two edges. How this could be possible? </div><div><br></div><div>I also attached an image of it, the thin white line (edge) in the black region is the confusing point. The given parameters are: alpha=-3, beta=3. <br></div><div><br></div><div>Hope to receive your helpful suggestions. Thanks in advance. </div></div></body></html>