In order to provide a fundamental understanding of cloth surface smoothness, the wrinkle components in the AATCC standard replica were studied. Using an image acquisition system with a line light source and a camera, images of the replica were obtained. Four images of each replication were taken at intervals of $90^{circ}$ degree rotations. The wrinkle ridges in the image were extracted using Canny edge detection, while the shade generated by the wrinkles was obtained using line threshold method. The ridge density, the distribution of ridge-to-ridge distance and the shade length distribution were measured and calculated. The three factors measured showed a strong non-linear relationship with the replication grades.