Chun-Shien Lu, Wen-Liang Hwang and Pau-Choo Chung
We propose a new method to estimate the surface orientation of a planar texture under perspective projection based on the ridge surface of 2D continuous wavelet transform (CWT) with rotations. We show that textural information giving the perception of surface orientation can be characterized from ridge surfaces in the space/frequency space. Three variants of ridge detection algorithm are presented. In order to deal with the weakly-ordered and disordered textures, robust regression method (RANSAC) is introduced to solve the problem. A closed-form solution is derived to determine surface orientation. The effectiveness of our method are demonstrated on several real-world textured images.