Comparison of Gradient, Gradient Vector Flow and Pressure Force for Image Segmentation Using Active Contours

When used as the image force for active contours, the gradient has the disadvantage of having a restricted capture range. Two solutions for improving the capture range, gradient vector flow and pressure forces, were compared. Although GVF provides a good capture range, it sometimes leads to boundary delocalisation. As an alternative, pressure forces have shown promising results for histological middle-ear images. The use of open contours was also demonstrated, in addition to the usual closed contours.