Abstract: Reference processing may be used in a video encoder or decoder to derive reference pictures that are better correlated with a source image to be encoded or decoded, which generally yields better coding efficiency. Methods for filter selection for a reference processing unit adapted for use in a video codec system are discussed. Specifically, methods for filter selection based on performing motion estimation and obtaining distortion/cost information by comparing reference pictures, either processed or non-processed, with the source image to be encoded are discussed.