title: Color Correction Parameter Estimation on the Smartphone and Its Application to Automatic Tongue Diagnosis.
abstract: BACKGROUND
  An automatic tongue diagnosis framework is proposed to analyze tongue images taken by smartphones. Different from conventional tongue diagnosis systems, our input tongue images are usually in low resolution and taken under unknown lighting conditions. Consequently, existing tongue diagnosis methods cannot be directly applied to give accurate results.
  
  
  METHODS
  We use the SVM (support vector machine) to predict the lighting condition and the corresponding color correction matrix according to the color difference of images taken with and without flash. We also modify the state-of-the-art work of fur and fissure detection for tongue images by taking hue information into consideration and adding a denoising step.
  
  
  RESULTS
  Our method is able to correct the color of tongue images under different lighting conditions (e.g. fluorescent, incandescent, and halogen illuminant) and provide a better accuracy in tongue features detection with less processing complexity than the prior work.
  
  
  CONCLUSIONS
  In this work, we proposed an automatic tongue diagnosis framework which can be applied to smartphones. Unlike the prior work which can only work in a controlled environment, our system can adapt to different lighting conditions by employing a novel color correction parameter estimation scheme.
authors.affiliation: Department of Computer Science and Information Engineering, National Cheng Kung University, Tainan, Taiwan. anita_hu@mail.ncku.edu.tw.
authors.forename: Min-Chun
authors.initials: MC
authors.lastname: Hu
authors.affiliation: Department of Computer Science and Information Engineering, National Cheng Kung University, Tainan, Taiwan. ktwjohn9527@gmail.com.
authors.forename: Ming-Hsun
authors.initials: MH
authors.lastname: Cheng
authors.affiliation: Department of Computer Science and Information Engineering, National Cheng Kung University, Tainan, Taiwan. klan@csie.ncku.edu.tw.
authors.forename: Kun-Chan
authors.initials: KC
authors.lastname: Lan
mesh_terms: D003116:Color; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation*; D008029:Lighting; D008516:Medicine, Chinese Traditional / Q000295:instrumentation*; D012044:Regression Analysis; D000068997:Smartphone; D060388:Support Vector Machine; D014059:Tongue / Q000503:physiopathology*
keywords: Color correction; Lighting condition estimation; Tongue diagnosis; Tongue segmentation