Video logarithmic tone mapping operator with automatic calculation of the logarithmic function base

High Dynamic Range (HDR) videos are intended to capture the full range of luminance that can be found in a real world environment. But, as display devices with restricted luminance range are still the most common ones, the need for efficient tone mapping tools remains. Applying a variable base logarithmic compression curve on HDR values is a method that gives good results on static images. Video mapping requires further processing, in order to maintain correct contrast over the different frames and to minimize undesirable artifacts such as flicker and temporal incoherencies when the overall lighting conditions vary. This paper describes a new method for a real time automatic calculation of the logarithmic function base, depending on the characteristics of successive frames in a sequence. Compared to some well-known operators, our proposal better performs in terms of temporal coherency and overall contrast.