Live-Wire Segmentation with "shortest path"

By Ilan Smoly

What is segmentation?

Approaches with graphs

• Intelligent scissors and Live wire - Optimal path (Dijkstra)

• Binary images posteriori estimation – Min-cut/Max-flow• Seeds – Min-cut/Max-flow with user inputs.

Live - Wire

The graph

• Oriented Boundary• Intelligent Scissors

Oriented Boundary

• Intensity• Various gradient magnitude• Orientation-sensitive

Intelligent Scissors

• Laplacian Zero-Crossing• Magnitude:• Gradient Direction

Shortest path with Laplacian cost

Livewire on the Fly

• A pruning of Dikstra• Stops when target is reached

Results

Results

directionality

Magnitude

Power

• No magnitude• No Directionality • No Power

• Directionality = 13 • Power = 30• Magnitude = 43

Discussion

• powerful and efficient tool for image editing and analyzing.

• Medical use• Not reliable for long distance pathways

Improvement

• random long distance relations between pixels

• Adopting the biological model