Fast and robust spatio-temporal image alignment for inter-sequence error concealment

Terrestrial broadcasting of digital TV is often error-prone due to suboptimal channels. Inter-sequence error concealment is a novel technique to reconstruct lost image blocks of video signals by inserting error-free blocks of reference signals. Considering multi-broadcast receivers, reference signals are typically scaled, cropped and delayed. Spatio-temporal image alignment therefore is the crucial point of inter-sequence error concealment. A well-known intensity-based approach utilizing a numerical optimization technique shows supreme reconstruction quality outperforming state-of-the-art concealment methods by up to 15 dB PSNR_Y. In this paper, we present a novel feature-based approach which significantly reduces complexity. By using scale-invariant features for image alignment, the computation time can be reduced by a factor of up to 32.4. As reconstruction quality is almost kept constant, robustness of our algorithm is high. The maximum loss is 0.8 dB in terms of PSNR_Y.