1. A method comprising: determining an attribute for a region of a picture, the picture having a particular resolution and the attribute being specific to the particular resolution and to the region, wherein the region of the picture is coextensive with a first integer number of pixels in the particular resolution, and coextensive with a second integer number of pixels in a second resolution; and converting the attribute to provide an attribute specific to the region and to a combination resolution determined as a combination of the particular resolution and the second resolution.