Abstract: A device comprising an image processor apparatus, the image processor apparatus being configured for implementing an image based computational model as part of an end-to-end processing pipeline. The device is configured to operate by receiving colour-specific image data representing a scene, receiving depth data of the scene, processing the colour-specific image data using the image based computational model to form a feature map of the scene, and forming in dependence on the feature map and the depth data an illumination map representing an estimation of the illumination on a set of three-dimensional locations in the scene.