Synchronization of Image Sequences - A Photogrammetric Method
2009
Raguse, Karsten | Heipke, C. (Christian)
<p><i>The three-dimensional photogrammetric analysis of image sequences is a growing field of application. For the analysis of dynamic processes one important precondition has to be guaranteed: All cameras have to be synchronized, otherwise the results are affected by asynchronism. In this article a new method is presented, which can determine the asyn-chronism of an arbitrary number of image sequences. In contrast to already existing methods, in the new approach the asynchronism is modeled in object space and then converted into an interpolation function containing a set of unknowns for each camera. In this form the asynchronism is introduced into an extended bundle adjustment, in which the unknowns are solved simultaneously with the image orientation parameters and the object coordinates of tie points. Therefore, the approach has no restrictions with regard to the number and the set-up of the cameras in the acquisition network. Furthermore, both the temporal and spatial analysis step are carried out simultaneously.</i></p><p><i>We have implemented the suggested method and have run anumber of experiments in the context of vehicle impact testing. First, sequences with a frame rate of 1,000 Hz observing an object with a speed of up to 7 m/s and an asynchro-nism of 0.8 ms were analyzed. The accuracy of the object point determination could be improved by a factor of 10. Then, five sequences of a vehicle impact test with a speed of 15.6 m/s were investigated. Here, errors in the object coordinates of up to 30 mm could be eliminated using the new approach. Given the small tolerances in car development, this improvement in point accuracy is significant.</i></p>
显示更多 [+] 显示较少 [-]