4D ISIP: 4D Implicit Surface Interest Point Detection

In this paper, we proposed a new method to detect 4D spatiotemporal interest point called 4D-ISIP(4 dimension implicit surface interest point). We implicitly represent the 3D scene by 3D volume which has a truncated signed distance function (TSDF) in every voxel. The TSDF represents the distance between the spatial point and object surface which is a kind of implicit surface representation. The basic idea of 4D-ISIP detection is to detect the points whose local neighborhood has significant variations along both spatial and temporal dimensions. In order to test our 4D-ISIP detection, we built a system to acquire 3D human motion dataset using only one Kinect. Experimental results show that our method can detect 4D-ISIP for different human actions.