Even Simpler Tone Curves

Bennett, James and Finlayson, Graham D. (2024) Even Simpler Tone Curves. In: London Imaging Meeting 2024: Image Capture, 2024-06-27 - 2024-06-28, Institute of Physics.

Preview

PDF (LIM_2024__Even_Simpler_Tone_Curves) - Accepted Version Available under License Creative Commons Attribution. Download (1MB) | Preview

Abstract

Abstractly, a tone curve can be thought of as an increasing function of input brightness which, when applied to an image, results in a rendered output that is ready for display and is preferred. However, the shape of the tone curve is not arbitrary. Curves that are too steep or too shallow (which concomitantly result in too much or too little contrast) are not preferred. Thus, tone curve generation algorithms often constrain the shape of the tone curves they generate. Recently, it was argued that tone curves should - as well as being limited in their slopes - only have one or zero inflexion points. In this paper, we propose that this inflexion-point requirement should be strengthened further. Indeed, the single inflexion point-only constraint still admits curves with sharp changes in slope (which are sometimes the culprits of banding artefacts in images). Thus, we develop a novel optimisation framework which additionally ensures sharp changes in the tone curves are smoothed out (technically, mollified). Our even simpler tone curves are shown to render most real images to be visually similar to those rendered without the constraints. Experiments validate our method.

Item Type:	Conference or Workshop Item (Paper)
Faculty \ School:	Faculty of Science Faculty of Science > School of Computing Sciences
UEA Research Groups:	Faculty of Science > Research Groups > Colour and Imaging Lab
Depositing User:	LivePure Connector
Date Deposited:	12 Jul 2024 11:30
Last Modified:	12 Jul 2024 11:30
URI:	https://ueaeprints.uea.ac.uk/id/eprint/95894
DOI:

Downloads

Actions (login required)

View Item