Visualization of Textile Surface Roughness Based on Silhouette Image Analysis

This paper presents a digital imaging method based on silhouette image analysis to visualize the 3D surface roughness of textile or other flexible materials. A prototype of imaging system consisting of five components was developed: visible lighting source (white backlighting), sample stage, progressive sample feeding equipment, detector (CCD camera) and software. A sequence of silhouette images of textile surface patches could be digitalized progressively when the sample passes through the sharp edge of crossbeam in bending status, so that the whole 3D surface profile could be generated by the combination of silhouette height profile of each surface patch in sequence. This non-destructive testing method is effective for surface roughness characterization or defects detection of flexible materials; it could reconstruct a pure 3D surface profile of textile surface while discarding the information of surface color so as to avoid the fusion of shadows and dark colors, which is impossible to be implemented based on the traditional 2-D image analysis.