Dyadic Spatial Re-sampling Filters for Scalable Video Coding

The patent extracts and eliminates the complex phase calculation component from the ESS re-sampling process by using a simplified filter bank approach. Instead of performing complex phase calculations for each sub-band, the invention uses a set of fixed filters that inherently handle the re-sampling operation, thereby reducing computational complexity while maintaining spatial scalability.

The patent changes the parameters of the re-sampling process by using a fixed filter bank with specific tap values (e.g., [−1, 17, 32, 17, −1]/64) instead of variable phase calculations. This parameterization approach allows the system to achieve dyadic spatial scalability through simple filter application rather than complex adaptive phase rotation.

The patent merges the low-pass filtering operation with the re-sampling filter application. Instead of applying separate low-pass filtering stages for sub-pixel interpolation, the invention combines these operations into a single filter bank application, thereby reducing the total number of operations and power consumption while maintaining interpolation accuracy.

The patent uses a partial filtering approach where the filter bank taps are designed to provide sufficient interpolation accuracy without requiring excessive filtering. The specific tap values (e.g., [−5, 0, 21, 32, 21, 0, −5]/64) are optimized to achieve the required precision with minimal computational effort, avoiding over-filtering and associated power costs.