Software System Research And Development Of The Fabric Drapability 3-Dimensional Tester

Fabric drapability is a kind of drape performance with the effect of gravity, It shows the fabric drape capability and drape status, It is also a evaluation index of visual style and aesthetics coziness ability. So, it is of great importance to research for the drapability of fabric, a important field is to develop effective test equipment.This paper gives brief review of the orientation and status quo of fabric drapability research, Introduces the Fabric Drapability 3-Dimensional Tester's essential structure and the principle of testing, Mainly discusses the system software design and implementation of the Fabric Drapability 3-Dimensional Tester. This system software was developed on Visual C++ 6.0 version, it includes four modules as follows: image collection and parameter adjusting, image analysis and processing, 3-D image reconstructing and system emulation, electronic devices control.In the module of image collection and parameter adjusting, the following functions are completed: detecting the CCD camera and connecting it, displaying the image, capturing and saving image, adjusting CCD gains of RGB channel and exposure time of sensor, adapting the preview window and capture window size, modifying the brightness, contrast, hue and saturation, preprocessing the image such as enhancement, filtering, sharpening.In the first part, two methods to locate the object fabric have been proposed, and the coordinate of the circular tray center and edge are obtained by each of the methods. Aferward, the sample fabric's contour points sequence is extracted by the steps of image preprocessing, contour point sampling and contour point sequence correcting. According to features of the printing fabric, a GVF Snake edge detecting module has been introduced to recognize the edge of the sample fabric. And this edge detecting module has been compared with the method based on the edge gradient sampling. The GVF Snake edge detecting module has greater adaptability, but it is too complex to implant. Finally, a method of function fitting the sample fabric's contour points sequence by Best n-th Degree Trigonometric Polynomial Approximation is firstly introduced. The experiments proved that the analysing of the discrete points can be translated into the analyzing of the multinomial trigonometric function, and the extracting of the evaluation parameter reflecting fabric drapability can be easier and more accurate.In the module of 3-D image reconstruction and system emulation, the following functions are realized: to determine 3-D image reconstruction algorithm and implement it, to accomplish 3-D image emulation, to present a way to deal with special samples, to explain how to fulfill a test process. A new algorithm was designed to locate the raster stripes in the image: using logic 'And' pen drawing radius, which will intersect raster stripe at point of intersection, for these points, it is very easy to determine 3-D coordinates: x and y are from the pixel position in the image, z is computed by the raster stripe order and the space of two raster stripes. A brief presentation of visual system emulation technology, common algorithms for 3-D emulation and 3-D emulation graphics library was quoted. A Bezier curved surface mathmatics model of sample drape shape was built, using this model reconstructing fabric drapability hood face, a 3-D fabric drapability emulation image can be completed.In the module of electronic devices control mainly includes the following functions: controlling step motor for running directions, spin speed and start-stop, sending signal for external exposure flash lamp, recommending a group of test steps, managing test result data, printing test report, correcting optical perspective error. Providing simple but effective management of data, interactive test process. In addition, a optical perspective error correcting algorithm was designed to modify geometry aberration and perspective error.If the Fabric Drapability 3-Dimensional Tester has only hardware without match software, it could not be used to test. So, the purpose, significance and importance of this thesis are obvious. To expand the functions of this software, perfecting database management module, when designers want to choose fabric by drapability, all the task can be done by sitting in front of a computer screen.