Figure 2.

HCT applied to a 3 × 3 image. In the case that pixel f ₂₂ indicates a true uptake (gray), the solid line is the true border and HCT algorithm iteratively averages its value with the pixels in the first column. In the case that dotted line is the true border, the uptake in pixel f ₂₂ iteratively averages its value with the pixels in the second and third columns.