Video Coding OOB Checks for Accurate Bi-Directional Compensation

The patent performs OOB checks before the bi-directional motion compensation process to identify and exclude invalid reference samples in advance. This preliminary action prevents the use of OOB samples in prediction, improving accuracy without requiring complex runtime checks during the compensation process itself.

The patent extracts and removes OOB samples from the reference blocks before they are used in prediction. By identifying samples that fall outside picture boundaries and excluding them from the prediction process, the method ensures only valid samples contribute to the prediction, resolving the contradiction between using all samples (low complexity) and using only valid samples (high accuracy).

The patent applies OOB checks selectively to specific regions and samples within reference blocks rather than uniformly to all blocks. By performing checks only where boundary conditions are relevant and using representative pixel positions for sub-blocks, the method improves prediction accuracy in critical areas while minimizing unnecessary computational overhead in other areas.

The patent performs OOB checks at representative pixel positions for sub-blocks rather than every single pixel position. This partial action approach provides sufficient accuracy for prediction while significantly reducing the computational overhead compared to checking every sample, resolving the contradiction between thorough checking and computational efficiency.