Preliminary Study On Evaluation Index Of Female Body Shape Based On "Three-Dimensional Measurement Theory Of Umbilical Point"

Objective: To propose a new body morphology measurement index system based on image for three-dimensional anthropometry,which is beneficial to the processing and analysis of three-dimensional coordinate data with umbilical point as origin and human markers,and to provide reference for body morphology measurement.At present,different body shape indicators are relatively single in evaluating human body shape.They do not take human body shape into account comprehensively and reflect one-sided problems.Therefore,based on the "umbilical point three-dimensional measurement theory",taking the umbilical point as the coordinate O point,this paper establishes the three-dimensional coordinate system of human body,lays the foundation for further exploring and evaluating the body shape index,provides the basic data basis for human development research and athlete selection,and provides the reference for human body aesthetic research.Method: The subjects of this study were female college students in Xi'an Institute of Physical Education.They were randomly selected from 30 female college students,aged 20.11±1.451.The experimental method consists of three parts: contact measurement(manual measurement),body fat rate measurement and non-contact measurement(mirror combined Photogrammetry System measurement).In the part of mathematical statistics,the T-test method is used to test whether there is a significant difference between the results of the mirror combined photography system and the contact measurement.The correlation analysis and kappa test are used to test the five indicators of the obesity evaluation.It can be seen that the 30 female college students are selected to evaluate their body shape.Whether there are differences or not;Coreldraw X4 software is used to mark the two-dimensional coordinates of the human body marker points in digital photographs with the umbilical point as the origin,and the two-dimensional coordinates are transformed into three-dimensional coordinates by Excel 2018,which is imported into Origin 2018 software to process the three-dimensional spatial data of human body.Result:(1)By comparing the results of contact measurement with those of mirror combined photography system,the results of two measurement methods for shoulder width and lower limb length of 14 indexes(P > 0.05)and the results of the other 12 indexes(P < 0.05).Comparing the error o f contact measurement with that of mirror combined photography system,the difference rate of height,upper limb length and hand length is within 1%-3%,and the difference rate of the remaining nine indexes is more than 3%.(2)In the comparative analysis o f different body shape indicators,the body shape indicators BMI,WC,WHR,BF and WHtR of 30 female college students were correlated with each other,and had a high significance(p < 0.01).Obesity was detected in 4 female college students when using BMI method to evaluate obesity,the detection rate of obesity was 13.3%.Obesity was detected in 5 female college students when using WC method to evaluate obesity.The detection rate was 16.7%.Six obese subjects were detected by WHR method,and the detection rate was 20%.Thirteen obese subjects were detected by BF method,and the detection rate was 43.3%.Eight obese subjects were detected by WHtR method,and the detection rate was 26.7%.BMI method and WC method have high consistency in judging female college students' obesity,BMI and WHR have medium consistency in judging female college students' obesity,BMI and BF have poor consistency in judging female college students' obesity.BF and WHR had moderate consistency in judging female college students' obesity,while BF and WC had no statistical significance in judging female college students' obesity(p > 0.05);WC and WHR had moderate consistency in judging female college students' obesity,while BMI and WC had ideal consistency in judging female college stude nts' obesity;BMI,WC,WHR,BF and WHtR had good consistency in judging female college students' obesity.The consistency was moderate.(3)The apical angle of umbilical point-bilateral lobe point is highly correlated with WC and WHtR,and moderately correla ted with BMI and BF;the apical angle of umbilical point-bilateral eye angle is moderately correlated with WHR,WC,BMI,WHtR and BF;the apical angle of umbilical point-thoracic prominence point is moderately correlated with WHR,WC,WHtR and BF;There was a moderate negative correlation between the apical angle f formed by the prominent points on both sides of the point-buttock and BF,and the apical angle I formed by the umbilical point-left lateral malleolus was moderately correlated with BMI and BF.(4)Programming with Origin 2018 software,the point matrix of three-dimensional coordinate points and the matrix of coordinate index of three-dimensional mesh are used to get the three-dimensional scatter point set graphics of 40 representative parts in the experimental group.(5)The following geometric figures were obtained by processing the obtained photographs: ellipse(apex of head,lobe of left and right ears,mandibular point),triangle(mandibular point and acromial point on both sides),trapezoid or irregular quadrilateral(acromial point and nipple height on both sides,prominent points on both sides of thorax),trapezoid or irregular quadrilateral(nipple height,prominent points on both sides of thorax and the finest points on both sides of waist),trapezoid.(The finest point on both sides of the waist and the height of the flat umbilical point on both sides of the waist),trapezoidal(the height of the flat umbilical point on both sides of the waist and the protrusion on both sides of the buttock),trapezoidal(the protrusion on both sides of the buttock and the depression on on both knees),trapezoidal or rectangular(the depression on on both knees and the protrusion on both sides of the leg),trapezoidal(the protrusion on both sides of the leg a nd the lateral ankle points on.Conclusion:(1)The accuracy of contact measurement and mirror combined photogrammetry is different.The measurement of some data with mirror combined photogrammetry system is more accurate than traditional measurement.Therefore,it can be used for mutual reference in the measurement process.The application of mirror combined Photogrammetry System in body shape measurement needs to be further improved.(2)Five indexes of body shape(BMI,BF,WHR,WHtR,WC)were different in evaluating the consistency of obesity among 30 female college students.(3)The apical angle a,b,D data of umbilical point-bilateral eye angle,umbilical point-bilateral earlobe point and umbilical point-thoracic protrusion point can be considered as the index of body shape evaluation.(4)The scatter set of human body obtained by origin 2018 software can clearly see the basic framework of human body from 40 representative scatter maps on the front and back.With the help of software,the three-dimensional model of human body can be roughly described,which lays a foundation for further study of body shape index.(5)Construct the geometric figure of the human body from the obtained photographs.The figure of the human body can be clearly seen from the constructed pattern map,which can provide reference for the evaluation of human beauty.