An automated image-based technique for tracking sequential surface wave profiles

Fast-deforming steep surface wave profiles are of particular interests to the design of marine structures and validation of numerical models. In this paper, an improved active contour model, gradient vector flow (GVF) snake, is adapted to automatically track sequential wave profiles taken by a non-intrusive high-speed imager. The robustness and efficiency of the adapted GVF snake is demonstrated through accurately delineating temporal and spatial wave profiles of three examples, including a spiller, a plunger, and a plunging breaker striking a vertical cylinder. Detailed characterizations to these breaking surface wave profiles are given. Overall, the automated adapted GVF snake imaged-based technique is shown to be a power tool for measuring surface wave motions and interfacial flows. (C) 2004 Elsevier Ltd. All rights reserved.