The Research On Fabric Drape Measurement System Based On Image Processing And Virtual Instrument

The drape is an important property of the fabric which is used in garments. In fabric drape testing instruments, the drape parameters of textiles can be got from the image of fabric drape edge, which can be obtained by the downward projection method. These parameters are used to express the drape performance of the fabric. Some gauffers of flexible fabric go to the right place below the supporting disc. The gauffers are shielded by the supporting disc in the down-ward projection image when the fabric is tested by the traditional instruments. Those would make unavoidable errors.In this paper, the fabric testing platform based on up-ward projection is built, and the fabric drape image can be collected by the up-ward projection method. This can be used to eliminate the unavoidable errors, which are occurred when the traditional down-ward projection testing method is used to measure the light, thin and soft fabric. After analyzing the application of digital image processing, the key processes, as well as the special method used in each processing step of the drape image, are presented and discussed in detail and the satisfying results are obtained.The fabric drape testing program can be written by LabVIEW7.1 and the IMAQ module. The fabric draping edge coordinate values can be obtained by the fabric drape image which is collected with the testing platform. After calibrating the camera using a simple calibration method, the general camera model is deducted and the correcting algorithm to rectify the distorted fabric drape image is built, which is in turn used to correct the distorted data and calculate the parameters of the fabrics. Furthermore, the factors which may-affect the accuracy of the fabric drape testing platform based on up-ward projection are analyzed. The measures and methods are proposed to reduce the testing system errors, and the formula to evaluate the system errors are also presented.The experiments are carried out on the traditional fabric drape testing instrument and the new fabric drape testing platform with some textiles which have different drape performance. After comparing and analyzing the result of the experiments, the conclusion can be drawn that the new testing method based on the up-ward projection can avoid the system errors, which are occurred when the traditional down-ward projection testing method is used to measure the light, thin and soft fabric, since the gauffers are bent below the supporting disc and are sheltered by it. The new testing platform would be a practical fabric drape measurement instrument, if some improvements were made on it. Using the coordinate data of the draping fabric edge and the equation of the draping fabric section, the 3D configuration of the draping fabric is reconstructed in the computer. This makes some foundations of the research on the draping fabric 3D configuration.