Developing HDR Tone Mapping Operators Based on Uniform Colour Spaces

Abstract

To perform tone mapping from high dynamic range images to standard dynamic range, scene luminance is typically used. The lightness or brightness from uniform colour spaces (UCSs) are hardly used. In this study, the role of the UCSs was evaluated by transforming the HDR radiance map to a particular colour space, followed by tone mapping of brightness, lightness or intensity channel of that colour space. Four UCSs, CIELAB, CIECAM02, IPT and recently developed Jzazbz were used in tone mapping. The image was first decomposed into large scale variation base layer and detail layer. The tone curve was applied on the base layer while detail layer was enhanced by local adaptation. The author’s newly developed method to evaluate TMOs was used to develop new TMOs by minimizing the CIELAB(2:1) colour difference between the TMO and the reference images.