RECODE: Revision Control for Digital Images

Revision control is a vital component in the collaborative development of artifacts such as software code and multimedia. While revision control has been widely deployed for text files, very few attempts to control the versioning of binary files can be found in the literature. This can be inconvenient for multimedia applications that use a significant amount of binary data, such as images, videos, meshes, and animations. Existing strategies such as storing whole files for individual revisions or simple binary deltas, respectively consume significant storage and complex semantic information. To overcome these limitations, in this paper we present RECODE, a revision control system for digital images. It stores revisions in the form of a DAG (directed acyclic graph) where nodes represent editing operations, and edges describe the spatial and temporal relationships between operations. Being integrated with GitHub, the largest project hosting platform, RECODE also facilitates the artistic creation process of distributed teams with different workflows that include image editing and digital painting. A preliminary user study was performed to assess the perceived usability of the proposed system.