the updated set of seeds as input.

![ segmentation prototype user interface. The current segmentation’s contour line (light blue) is [adjusted towards the user’s estimate of the ground truth segmentation]{} by manually adding foreground (blue) or background (red) seed points.[]{data-label="fig:semi-manual_prototype"}](images/semi-manual_segmentation_prototype_contrast.png){width="\columnwidth" height="0.61296534017\columnwidth"}

### Guided Segmentation Prototype {#sec:guided_prototype}

The system selects two seed point locations , each with the lowest label certainty values assigned by the previous segmentation process. The seed point locations are shown to the user in each iteration $n$, as depicted in **Fig.**\[fig:guided\_prototype\]. There are four possible labeling schemes for those points in the underlying classification problem, since each seed point has a label . The interface providing advanced user guidance displays the four alternative segmentation contour lines, which are a result of the four possible next steps during the iterative interactive segmentation with respect to the labeling of the new seed points $\mathbf{s}^n_1$ and $\mathbf{s}^n_2$. The user selects the only correct labeling, where all displayed object and background seeds are inside the object of interest and the image background, respectively. The alternative views on the right act as four buttons to define a selection. To further assist the user in their decision making, the region of interest, defined 