1. A method of manipulating a two-dimensional digital input image using an image operator that represents a change in a lighting characteristic, wherein the image operator is calculated based on a score offset indicative of a desire to manipulate the lighting characteristic in the input image by a particular degree and a mapping derived from an association between characteristics of aligned two-dimensional digital images in a dataset and at least one score allocated to each of a plurality of the images in the dataset, each score representing a degree of the lighting characteristic in the image, and wherein the image operator and the input image are aligned, and wherein the dataset of images comprises images of different subjects, the method comprising: receiving a request comprising a score offset indicative of a desire to manipulate the lighting characteristic in the input image by a particular degree; applying a calculated image operator to the input image based upon the received score offset to produce a manipulated input image which corresponds to the input image but with the lighting characteristic manipulated.