is expected to choose the upper-right option in this configuration, [due to the two new seeds’ matching background and foreground labels]{}.[]{data-label="fig:guided_prototype"}](images/guided_segmentation_prototype_contrast.png){width="\columnwidth" height="0.61296534017\columnwidth"}

### Joint Segmentation Prototype {#sec:joint_prototype}

The joint prototype depicted in **Fig.**\[fig:joint\_prototype\] is a combination of a pictorial interaction scheme and a menu-driven approach. (1) A set of pre-selected new seeds is displayed in each iteration. The seeds’ initial labels are set automatically, based on whether their position is inside (foreground) or outside (background) the current segmentation mask. The user may toggle the label of each of the new seeds, which also provides an intuitive functionality. The automated suggestion process for new seed point locations is depicted in **Fig.**\[fig:joint\_prototype\_prob\_map\]. The seed points are suggested deterministically based on the indices of the maximum values in an element-wise sum of three approximated influence maps. These maps are the gradient magnitude image of $\mathbf{I}$, the previous label changes per element in $\mathbf{G}_\mathbf{I}$ weighted by an empirically determined factor of $17/12$, and an influence map based on the distance of each element in $\mathbf{I}$ to the current contour line. Note that for the guided prototype (see **Sec.**\[sec:guided\_prototype\]), only $\mathbf{h}$ was used for the selection of suggested seed point locations. This scheme was extended 