title: Unified approach for lesion border detection based on mixture modeling and local entropy thresholding.
abstract: OBJECTIVE
  Computer-aided design (CAD) methods are highly valuable for the analysis of skin lesions using digital dermoscopy due to low rate of diagnostic accuracy of expert dermatologist. In computerized diagnostic methods, automatic border detection is the first and crucial step.
  
  
  METHODS
  In this study, a novel unified approach is proposed for automatic border detection (ABD). A preprocessing step is performed by normalized smoothing filter (NSF) to reduce background noise. Mixture models technique is then utilized to initially segment the lesion area roughly. Afterward, local entropy thresholding is performed to extract the lesion candidate pixels and the lesion border is smoothed using morphological reconstruction.
  
  
  RESULTS
  The overall ABD system is tested on a set of 100 dermoscopy images with ground truth. A comparative study was conducted with the other three state-of-the-art methods using statistical metrics. This ABD technique has the minimal average error probability rate of 5%, true detection of 92.10% and false positive rate of 6.41%.
  
  
  CONCLUSIONS
  Results demonstrate that the proposed method segments the lesion area accurately. Sample dataset and execute software are available online and can be downloaded from: http://cs.ntu.edu.pk/research.
authors.affiliation: Department of Computer Science, COMSATS Institute of Information Technology, Sahiwal, Pakistan. drqaisar@ciitsahiwal.edu.pk
authors.forename: Qaisar
authors.initials: Q
authors.lastname: Abbas
authors.forename: Irene Fondón
authors.initials: IF
authors.lastname: Garcia
authors.forename: M
authors.initials: M
authors.lastname: Emre  Celebi
authors.forename: Waqar
authors.initials: W
authors.lastname: Ahmad
authors.forename: Qaisar
authors.initials: Q
authors.lastname: Mushtaq
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D046169:Dermoscopy / Q000379:methods*; D019277:Entropy; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008954:Models, Biological; D015233:Models, Statistical; D010363:Pattern Recognition, Automated / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012878:Skin Neoplasms / Q000473:pathology*
keywords: computer-aided diagnosis; dermoscopy; entropy; lesion segmentation; mixture model; skin cancer