Distortion Evaluation and Data Extraction for Behavior Videos of Fishes
Zhao Yuan · Hunan Agricultural Sciences · 2011
The image distortion in behavior videos of fishes has been evaluated by means of nine control reference points with 12 distortion evaluation factors;two types of data extracting methods have been developed,one was based on perspective theory and the other one was based on shot with special equipment designed by the authors,the 3-D spatial position of individual fish can be accurately obtained from the video records.The results showed that(1) when the other shooting conditions were the same,the larger the shooting distance between camera and object was,the smaller the image distortion in the photos was;while the shooting distance was 5 m,the image distortion basically not affect extracting results of two kinds of data.(2) The method based on perspective theory could keep all 3-D information without any missing,but was not accurate enough while the fish was not exactly parallel to the front wall of tank.(3) The method by means of a special designed equipment was easier to use and accurate in measurements,but it would lose certain information when the fish was near or close to the wall of tank.