|
|
APAS-XP Extra PerformanceAPAS is designed to streamline and automate the process of biomechanical analysis from the starting point of collecting video data from multiple cameras to the point of displaying 3D image data.
Additionally various image enhancement algorithms are applied to the image that aid in the rejection of incorrect marker candidates. Additional algorithms further reject extraneous markers. Being able to track the markers in 3D is critical to the proper functioning of the algorithm. This means that each marker should be seen by at least 2 cameras at all times, however which 2 cameras may change. For this reason we recommend using 5 well spaced cameras. |
|
Central to APAS-XP is a completely new marker tracking system for
auto-digitizing the video sequences. This new auto-digitizing is called 3D
Auto-Track. Internally the software calculates and saves the 3D location of each
marker for each frame. Then for each point in a new frame a complex algorithm is
applied to the past 3D trajectory and an expected 3D location is computed. The
expected 3D location then is transformed to each camera view and the software
searches for markers starting at the expected location in the different camera
views. In this way the system "knows" where a marker should be in each view even
when it is not visible in a view. When a marker re-appears in a view after
potentially many missing frames the software will pick it up because the
software has been tracking in 3D.