Automatic seed selection

[danoan]

A naive implementation could be the following:

1. Run a contour-detection algorithm (likely one is biased to form closed contours)
2. Invert the image to obtain the connected digital sets
3. For each connected digital set, choose some strategy to select seeds in the interior (foreground) and in the outer (background) of the set.
4. Run the graph-flow for each connected digital set

An alternative to that:

1. Create an hierarchy (watershed segmentation)
2. Pick some nodes of the hierarchy to execute graph-flow
3. Select the best graph-flow result

The data term may be defined like this: For the closed areas, select random seeds and compute a mixed gauss distribution (similar to classical graph cut)