Automatic Assessment of Fabric Smoothness Grade Using Double CCD Grating Projection

Automatically assessing fabric smoothness grade is very important in the evaluation of fabric appearance. A system for objectively evaluating the fabric smoothness grade based on a grating projection unit and double colored CCD (short form of charge coupled device) was constructed in this paper. Two images captured by different CCD compensated each other which reduced the influence of noises. The application of the four-step phase-shifting method enabled the calculation of the exact phase in a point easy and quick. A large amount of 3D points with three coordinates X, Y and Z were obtained precisely making the definition and calculation of fabric smoothness characters easy. Then four parameters which intuitively denoted the fabric smoothness degree were obtained. Finally, a proper neural network was built, which successfully performed the fabric smoothness classification. The experimental results show that the system is applicable for all the fabric whatever pattern or color. The experimental grades provided by this grating projection system are also highly consistent with the subjective results.