Optimized tone mapping with flickering constraint for backward-compatible high dynamic range video coding
Backward compatibility to low dynamic range (LDR) displays is an important requirement for high dynamic range (HDR) image and video coding in order to enable a successful transition to HDR technology. In a recent work [1], an optimized solution for tone mapping and inverse tone mapping of HDR images and video frames is achieved in terms of the mean square error (MSE) of the logarithm of luminance values of HDR pixels for backward-compatible compression. Although this pioneer optimization approach provides a well settled mathematical framework for tone mapping, one of its important shortcomings is the flickering distortions that can occur on the resulting video due to the individual tone mapping applied to each frame. In this paper, we include the flickering distortion level as a constraint to optimization problem and develop a methodology to compromise the trade-off between the rate-distortion performance and flickering effect. The developed methodology is validated on HDR video sequences by showing the changes in rate-distortion performances with respect to the different flickering levels.