title: Evaluations of auto-focusing methods under a microscopic imaging modality for metaphase chromosome image analysis.
abstract: BACKGROUND
  Auto-focusing is an important operation in high throughput imaging scanning. Although many auto-focusing methods have been developed and tested for a variety of imaging modalities, few investigations have been performed on the selection of an optimal auto-focusing method that is suitable for the pathological metaphase chromosome analysis under a high resolution scanning microscopic system.
  
  
  OBJECTIVE
  The purpose of this study is to investigate and identify an optimal auto-focusing method for the pathological metaphase chromosome analysis.
  
  
  METHODS
  In this study, five auto-focusing methods were applied and tested using metaphase chromosome images acquired from bone marrow and blood specimens. These methods were assessed by measuring a number of indices including execution time, accuracy, number of false maxima, and full width at half maximum (FWHM).
  
  
  RESULTS
  For the specific condition investigated in this study, the results showed that the Brenner gradient and threshold pixel counting methods were the optimal methods for acquiring high quality metaphase chromosome images from the bone marrow and blood specimens, respectively.
  
  
  CONCLUSIONS
  Selecting an optimal auto-focusing method depends on the specific clinical tasks. This study also provides useful information for the design and implementation of the high throughput microscopic image scanning systems in the future digital pathology.
authors: Center for Bioengineering and School of Electrical and Computer Engineering, University of Oklahoma, Norman, OK 73019, USA.
authors: Yuchen
authors: Y
authors: Qiu
authors: Xiaodong
authors: X
authors: Chen
authors: Yuhua
authors: Y
authors: Li
authors: Wei R
authors: WR
authors: Chen
authors: Bin
authors: B
authors: Zheng
authors: Shibo
authors: S
authors: Li
authors: Hong
authors: H
authors: Liu
mesh_terms: D057205:Automation, Laboratory; D002877:Chromosomes, Human; D057166:High-Throughput Screening Assays; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007621:Karyotyping / Q000379:methods*; D008677:Metaphase; D008853:Microscopy; D011237:Predictive Value of Tests; D013647:Task Performance and Analysis; D013997:Time Factors; D057188:Workflow