Visual inspection of textile surfaces with translation invariant wavelet shrinkage

A visual inspection method of textile surfaces using the translation invariant wavelet shrinkage is presented. The wavelet transform, while the Mallat algorithm can compute it efficiently, has the translation variance problem. To deal with this problem, we use RI-spline wavelets, which are pseudo complex wavelets, consist of a pair of a symmetric bi-orthogonal spline wavelet and an anti-symmetric bi-orthogonal spline wavelet, for textile surface inspection. In our approach, we remove the regular information which consists of the textile textures and the shading effects caused by uneven lighting from the textile surfaces to be inspected, using the translation invariant wavelet shrinkage realized using 2D RI-spline wavelets. The experimental results show that our inspection method is effective for detecting tiny defects as well as global defects such as dyeing unevenness.