How to and how not to use graph cuts

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How to and how not to usegraph cuts

• Karen Liu and Brett Allen

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What graph cuts is good for

• Suppose you want to label the nodes in a graph

• For each node, you have
• a data term D(p, fp) the cost of labeling
  node p with label fp
• a neighbor term, V(fp, fq), the cost of labeling
  connected nodes p and q with labels fp and fq.

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The algorithm

• we used an existing min-cut implementation
• for each a-expansion, we build a graph that
  expresses the desirability of switching each
  nodes label to a ( )

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Application 1 Stripe labeling
A harder case
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Using graph cuts
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Results
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What went wrong?!
True labeling 11 12 13 14 15 16 17 18 19

Current labeling 11 12 13 1 2 3 17 18
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any a-expansion will not improve the energy!
a-expansion only works if
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Application 2 Stereo
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Using graph cuts
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Results
Ground truth
Graph cuts
Parameters 12 labels (12-34 pixel displacement),
w 10
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Results
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Results (2)
Input
Ground truth
Graph cuts
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Results (3)