A Procedure for the Analysis of Skiers' Movement with Image Processing Techniques

Abstract

Image processing techniques have been applied for analyzing the reasons for collisions among skiers in a ski area. The skiers images used are taken from analog video tapes recorded at Takamagahara ski area in Nagano Prefecture. These images digitized in the size of 128 × 128 and quantized into 256 gray levels. Skiers images are extracted from images sampled every 1/6 seconds. The optimal threshold level for segmenting the skiers image is calculated using the step by step method. The projected future position of skiers is calculated from the relation between the past and present positions. Procedures for extracting skiers images are as follows : (1) Divide an image into meaningful regions. (2) Label the segmented regions. (3) Reject all regions except for skiers. (4) Calculate the skiers' center of gravity. (5) Find the locus of skiers' movement. (6) Detect skiers' collisions. By these procedures, good results for detecting skiers' collisions can be obtained.