Application of Ridgelet Transform to Wave Direction Estimation

To extract wave direction from sea surface images, a new method is proposed, which is based on ridgelet transform. Due to the linear feature of sea wave images, this method first provides a pre-processing to take a disk shape area from the middle of the wave image. Then the wave direction which has an associated ±180 degree ambiguity is calculated using ridgelet transform. Meanwhile, a timestack image is collected from successive frames in specific orientation to track the wave propagation. Furthermore, the timestack is processed by ridgelet transform to find the forward wave direction. Lastly, the wave direction without degree ambiguity is determined effectively. The experiment results show the validity and feasibility of the method and good accuracy is achieved.