Meeting Abstract

P1.73  Friday, Jan. 4  Automated Shape Modeling for Undulatory Swimmers Using Blum’s Medial Axis WATERS, S P*; LEONARD, K; PORTER, M E; LONG, J H; LIEW, C W; ROOT, R G; Lafayette College; California State University, Channel Islands; Vassar College; Vassar College; Lafayette College; Lafayette College waterss@lafayette.edu

The swimming patterns of undulatory swimmers can be modeled by tracking changes in their medial axis. In the past, the process for extracting this axis from video consisted of time consuming manual analysis. Our research proposes to optimize collection of medial axis data via a mathematical model of the image. By identifying the outline of the swimmer in a video frame, we identify the medial axis through a series of computations based on the concept of a medial axis as first described by Blum. The algorithm depends upon two parameters, the rate at which outline points are chosen for inclusion in the computation, and the size of the contour ratio associated with each candidate medial axis point, and through these parameters, the algorithm can be applied flexibly in a wide array of video. To demonstrate the utility of the technique, we apply it to video clips of swimming fish of several species in a variety of situations.