A New Tone Mapping Workflow for High Dynamic Range Content

The use of High Dynamic Range (HDR) content is becoming increasingly popular in content creation and post-production. Advances in digital technology allow creating HDR content much easier than before. HDR display devices, on the other hand, are still not mature enough to become widely available. Therefore, HDR content has to go through a particular processing step, usually called tone mapping or tone reproduction, to be viewable on conventional displays. For most applications, the tone mapping process must usually fulfill two main requirements: keep details (local contrast) and maintain the sensation of brightness. There has been a great deal of work on HDR tone mapping algorithms during the last decade. However, existing tone mapping techniques focus on the first requirement and neglect the second one, usually the most important from the artist's perspective. Available tone mapping algorithms usually do not allow independently manipulating the tone of different part of a picture and thus they can rarely match the sensation of the original HDR content. In this paper, we propose a new scheme that meets the above two requirements. The proposed scheme is in spirit similar to the Zone System, a proven theory and practice used in traditional photography, and it can be seen as a computational model for the Zone System. The proposed scheme is also flexible enough to allow the user to easily control the look of differents parts of the picture, facilitating the creative process.