Wave swash velocity estimation using ridgelet transform

The measurement of nearshore wave swash and understand of wave swash characteristics are very important in nearshore environment research, coastal zone management and ocean engineering. To estimate swash velocity from nearshore video images, a computational algorithm based on ridgelet transform is proposed. In the proposed approach, a time stack image with linear feature of wave swash fronts is derived from specific slice position in the input image sequences. Then, edge detection is processed to enhance the image feature. Moreover, ridgelet transform is calculated and the energy is computed using variance statistics. Meanwhile, a peak angle is extracted as the direction of the linear feature of wave swash fronts. Furthermore, the swash velocity can be calculated with the linear slope. Experimental results indicate that the proposed methodology is effective and validity.