Curvature scale space based affine-invariant trajectory retrieval

In this paper, we outline a novel technique for robust indexing and retrieval of video object trajectories. Our approach is based on using spatio-temporal curvature to represent the trajectories. Dominant inflection points from the curvature are extracted at multiple levels of scale simultaneously revealing structure at varying levels of details. These inflection points, the maxima of Curvature Scale Space (CSS), are then used for indexing and retrieval. Experiments on a database containing trajectories of high jumps and other motions show the affine-invariant nature of our approach.