Objective Evaluation Of The Fabric Pleating Grade Based On Laser Point Cloud Data

Pleat has a variety of designs and changes in costume modeling,which can meet the basic needs of human activities,but also has the function of both practical and decorative,And pleating is a special form of flatness,which affects the appearance and effect of clothing.In the past,the standard of AATCC-88C was used to evaluate the pleat grade.However,this method was strict with the experimental conditions,the preparation process was cumbersome,and susceptible to the subjective factors of the evaluation,thus reducing the accuracy of the results.Therefore,it is very important to evaluate the fabric pleat grade objectively and accurately.At present,more and more image processing techniques are used to test and evaluate fabric flatness.As an emerging detection method,three-dimensional measurement technology can intuitively reflect the spatial location,vector information and outline shape of the measured object and facilitate the feature extraction,However,this method is applied to the evaluation of the degree of fabric pleat relatively small,so the use of this technology objective evaluation of the grade of the pleated fabric will be a trend.In view of this situation,this paper proposes a method of comprehensive indexes of objective evaluation of fabric pleat grade based on the standard AATCC-88C model as the research object,using a 3D laser scanner point cloud data obtained by linear fitting correlation feature parameter extraction and pleat grade,finally established the objective evaluation of fabric pleat grade the model using regression analysis method,The research contents and results are as follows:(1)The REV scan 3D laser scanner was used to obtain the 3D point cloud data of the standard pleat template AATCC-88C.Then,the data was reconstructed from the reference surface.The plane formed by the XY axis was taken as the new reference surface and the Z axis was taken as the pleat height.By extracted six characteristic parameters of quartile difference Q_d,average deviation R_a,roughness?,standard deviation S,distortion R_s and kurtosis R_k,the linear fitting between the single variable characteristic parameters and the pleating grade is carried out.Finally,the model of comprehensive characteristic indexes and fabric pleating grades established by stepwise regression analysis was:And the discriminant method comprehensive index evaluation result and pleat grade were compared,and the correlation coefficient was 0.91.(2)In order to compared with the result obtained by the objective test method of three-dimensional scanning,the standard images obtained under three light sources was processed by the two-dimensional image processing method and grayscale,The results showed that the gray values of the images under different light sources was quite different.Finally,the images obtained under the front light are selected,and the characteristic indexes was extracted and fitted to the pleat grade linearly,but the fitting result was not satisfactory.Then,the verification and analysis of the application of image processing technology to pleat grade was feasible by used the wavelet analysis method,used wavelet function to pleat image is decomposed into five layers,extraction grade,detail coefficients of standard vertical and diagonal directions on the difference of SH,SV and SD,The results showed that the correlation between the extracted index and the grade of pleating was not good.Therefore,the method of 3D laser point cloud processing is more suitable for the evaluation of fabric pleating grade.(3)Used C#language in Visual Studio 2010 compiler environment in the library,write"the application of fabric pleat grade objective evaluation system",The program includes point cloud data import,calculation of six eigenvalues,classification of pleats on fabrics,and derivation of major functional modules such as objective evaluation data.(4)Selected 50 pieces of fabric samples to verify the objective evaluation system of fabric pleat grade,Among them,there was 46 samples with the same subjective and objective results,that was,the fitting degree of the subjective and objective ratings of the fabric sample was 0.92,and the fabrics that do not match are almost printed fabrics.The subjective and objective evaluation results of all the pure color fabrics are identical.The feasibility and practicability of an objective evaluation system of fabric pleat grade based on 3D point cloud data was verified.