A Contour Tracking Algorithm for Rotoscopy

Rotoscopy is a crucial processing for cinema post-production. It corresponds to the segmentation of an object of interest in a video in order to apply a local processing. In the industry, rotoscopy is usually performed manually, frame by frame. Semi-automatic algorithms have been proposed to reduce the load of this task. However, they classically use contour-based information and consequently lack robustness in case of occlusion. Here, we propose a region-based contour tracking algorithm relying on feature points which are temporally matched to build trajectories used to estimate a global or local deformation between a distant reference contour and the current frame. Then, we propose a rotoscopy algorithm based on a forward and a backward contour tracking. The use of region information and distant reference contours allows to avoid drift and greatly reduce the influence of occlusions. The rotoscopy algorithm was applied to CEF and SD sequences