A method for transforming an image expressed in terms of a first image encoding to a second image encoding, includes converting a set of original scene exposure-factor values into corresponding first and second image encoding values. A transform is then derived between the first image encoding values and the second image encoding values. The transform is then applied to an image encoded in said first image encoding. Examples of different encoding that can be transformed include Rec. 709, sRGB and other known image encoding standards. A system for performing such transformations as well as an electronic device that is capable of performing such transformations are also disclosed.