Images to be used as reference images in an adaptive resolution coder or decoder undergo resizing to match the resolution of an image being processed. The resizing process is carried out using extended resolution bit lengths to more accurately represent the processed image. The internal bit depth is retained through the resizing process, and kept as a reference image is stored. When a reference image is used in motion compensation processing, the resized reference matches the resolution of a current image being processed and has an expanded bit depth precision to achieve better fidelity.