Constructor Detail

• GraphCut

  public GraphCut(int numNodes,
                  int numEdges)

  Initialises the graph cut implementation and allocates the memory needed for the given number of nodes and edges.

  Parameters:

  numNodes - The number of nodes that should be created.

  numEdges - The number of edges that you can add. A directed edge and its counterpart (i.e., the directed edge in the other direction) count as one edge.

Method Detail

• setTerminalWeights

  public void setTerminalWeights(int node,
                                 float source,
                                 float sink)

  Set the affinity for one node to belong to the foreground (i.e., source) or background (i.e., sink).

  Parameters:

  node - The number of the node.

  source - The affinity of this node to the foreground (i.e., source)

  sink - The affinity of this node to the background (i.e., sink)

• setEdgeWeight

  public void setEdgeWeight(int node1,
                            int node2,
                            float weight)

  Set the edge weight of an undirected edge between two nodes. Please note that you cannot call any setEdgeWeight more often than the number of edges you specified at the time of construction!

  Parameters:

  node1 - The first node.

  node2 - The second node.

  weight - The weight (i.e., the cost) of the connecting edge.

• setEdgeWeight

  public void setEdgeWeight(int node1,
                            int node2,
                            float weight1to2,
                            float weight2to1)

  Set the edge weight of a pair of directed edges between two nodes. Please note that you cannot call any setEdgeWeight more often than the number of edges you specified at the time of construction!

  Parameters:

  node1 - The first node.

  node2 - The second node.

  weight1to2 - The weight (i.e., the cost) of the directed edge from node1 to node2.

  weight2to1 - The weight (i.e., the cost) of the directed edge from node2 to node1.

• computeMaximumFlow

  public float computeMaximumFlow(boolean reuseTrees,
                                  List<Integer> changedNodes)

  Performs the actual max-flow/min-cut computation.

  Parameters:

  reuseTrees - reuse trees of a previos call

  changedNodes - list of nodes that potentially changed their segmentation compared to a previous call, can be set to null

• getTerminal

  public Terminal getTerminal(int node)

  Get the segmentation, i.e., the terminal node that is connected to the specified node. If there are several min-cut solutions, free nodes are assigned to the background.

  Parameters:

  node - the node to check

  Returns:

  Either Terminal.FOREGROUND or Terminal.BACKGROUND

• getNumNodes

  public int getNumNodes()

  Gets the number of nodes in this graph.

  Returns:

  The number of nodes

• getNumEdges

  public int getNumEdges()

  Gets the number of edges in this graph.

  Returns:

  The number of edges.

• markNode

  public void markNode(int node)

  Mark a node as being changed. Use this method if the graph weights changed after a previous computation of the max-flow. The next computation will be faster by just considering changed nodes. A node has to be considered changed if any of its adjacent edges changed its weight.

  Parameters:

  node - The node that changed.