A method of processing data in a multi-stage imaging pipeline, the method comprising, at each stage of the multi-stage imaging pipeline, identifying a plurality of encoding values represented in received input data in a given encoding space for the respective pipeline stage, the identified plurality of encoding values comprising a subset of encoded values which are capable of being represented in the given encoding space, generating a list of encoding indices corresponding to the identified plurality of encoded values in the given encoding space, representing the encodings of one or more entities of the received input data using the generated list of encoding indices, and outputting the represented encodings of the one or more entities to the next stage of the multi-stage imaging pipeline.