Anthropometric Analysis of Face using Local Gaussian Distribution Fitting Applicable for Facial Surgery

Human facial plays a very important role in the human’s appearance. Many defects in the face affect the facial appearance, significantly. Facial plastic surgeries can correct the defects on the face. Analysis of facial color images is very important due to its numerous applications in facial surgeries. Different types of facial surgeries, such as Rhinoplasty, Otoplasty, Belpharoplasty and chin augmentation are performed on the face to make beautiful structure. Rhinoplasty and Otoplasty are widely used in the facial plastic surgeries. the former is performed to correct air passage, correct structural defects, and make a beautiful structure on bone, cartilage, and soft nasal tissue. Also, the latter is performed to correct defects in the ear area. Development of different tools in the field of facial surgery analysis can help surgeons before and after surgery. The main purpose of this study is the anthropometry analysis of facial soft tissue based on image processing methods applicable to Rhinoplasty and Otoplasty surgeries. The proposed method includes three parts.; (1) contour detection, (2) feature extraction, and (3) feature selection. An Active Contour Model (ACM) based on Local Gaussian Distribution Fitting (LGDF) has been used to extract contours from facial lateral view and ear area. The LGDF model is a region-based model which unlike other models such as the Chan-Vese (CV) model is not sensitive to the inhomogeneity of image spatial intensity. Harris Corner Detector (HCD) has been applied to extracted contour for feature extraction. HCD is a method based on calculating of auto-correlation matrix and changing the gray value. In this study, dataset of orthogonal stereo imaging system of Sahand University of Technology (SUT), Tabriz, Iran has been used. After detecting facial key points, metrics of facial profile view and ear area have been measured. In analysis of profile view, 7 angles used in the Rhinoplasty have been measured. Analysis of ear anthropometry includes measuring the length, width and external angle. In the Rhinoplasty analysis, accuracy of the proposed method was about %90 in the all measurement parameters, as well as, it was %96.432, %97.423 and %85.546 in the Otoplasty analysis for measuring in the length, width and external angle of the ear on AMI database, respectively. Using the proposed system in planning of facial plastic surgeries can help surgeons in the Rhinoplasty and Otoplasty analysis. This research can be very effective in developing simulation and evaluation systems for the mentioned surgeries.