Vision-based feature extraction and analysis of a synchronized swimmer

• Main Author: Ong, Prane Mariel B.
• Format: text
• Language: English
• Published: Animo Repository 2009
• Subjects: Synchronized swimmers; Synchronized swimming; Swimming; Physics
• Online Access: https://animorepository.dlsu.edu.ph/etd_masteral/3812; https://animorepository.dlsu.edu.ph/context/etd_masteral/article/10650/viewcontent/CDTG004663_P.pdf
• Institution: De La Salle University

Vision-based feature extraction of a synchronized swimmer doing figures was done in hopes of correcting and improving synchronized swimmers ability to do figures. Extracted feature through image processing techniques plays an important role in understanding the synchronized swimmers body kinematics. A member of the synchroswan team performed three types of figures synchronized swimming. These are Porpoise, Neptunus and Ballerina. In gathering data, two cameras were used to video capture the swimmers movements. One was stationed at a calculated distance above the water, and the other camera was placed underwater directly above other camera. Image processing was done not in real time under the Matlab environment. Threshold limits were empirically extracted base from skin color region and it serve as a tool to feature extract the foreground from the background. Centroid of each column or row data was measured producing a segmental outline of the body. This is analogous to a stick figure representation of the swimmer. Toe-ankle segment, ankle-knee segment, kneehip segment and hip-shoulder segment were the anatomical segments that were observed. Centroid measurements were done only at the figure transitions indicated by the FINA Manual for Synchronized Swimming. From the centroid values, two points were extracted per segment to be used in angle calculation. The calculated angle, angular velocity and angular acceleration of each body segments were used to analyze the swimmers motion. Systematic error and random errors were also considered and noted. Angle information became an indicative factor of whether the sychro swimmer did hit a specific figure transition or not. These collected data are essential in analyzing the synchro swimmers performance.