A Registration Method Based on Contour Point Cloud for 3D Whole-Body PET and CT Images

Algorithm 3

Feature point cloud extraction.

Input: The feature image sequences FIS and the number of images contained by the sequences N.

Output: The feature point cloud sequences FPCS.

Steps:

() for id = 1 → N do    : the number of connected region contained by

  NCR[i] = countNumberOfConnectedRegion (FIS[i])

  end for

() for id = 1 → N do    : the slice id of the first slice with only 1 connected region in FIS

  if NCR[id] = 1 then M1 = id, break the circulation

  end if

  end for

() for id = N → 1 do    : the slice id of the last slice with only 1 connected region in FIS

  if NCR[id] = 1 then M2 = id, break the circulation

  end if

  end for

() for id = M1 → M2 do   : the feature points contained by

  FP[id] = extractFeaturePoints (FIS[id])

  writeCoordinatesOfFeaturePointsIntoPointCloudFile (FP[id], FPCS[id])

  end for