Occlusion aware digital colouring for comics

Abstract

A common workflow for modern comic artists is to create an inked line drawing using traditional tools. Then the drawing is scanned as black and white line art and coloured digitally using an application such as Photoshop [Abel and Madden 2012]. The first step of digital colouring, called flatting, assigns symbolic colours to each region in an image which a colourist can use to apply final colours and other effects. There is little direct support for flatting in software, which results in a manual, labour intensive process for artists. Further, an object in a drawing may be split into multiple regions due to occlusions, requiring an artist to assign the same colour to each region of the object. This work describes a quantitative framework that allows occlusion cues, derived from vision research, to be computed and compared with each other. This framework is used to simplify comic flatting, allowing an artist to flat multiple regions in a single click. Simple gestural tools that can be used to add additional guidance to occlusion processing are also provided.