Spatio-temporal constrained tone mapping operator for HDR video compression

With the growing popularity of high dynamic range (HDR) imaging, efficient compression techniques are demanded, as HDR video entails typically higher raw data rate than traditional video. For this purpose, we introduce a hybrid spatially and temporally constrained content-adaptive tone mapping operator (TMO) to convert the input HDR video into a tone mapped video sequence, which is then encoded using the high efficiency video coding (HEVC) standard. The proposed TMO simultaneously exploits intra-frame spatial redundancies and preserves inter-frame temporal coherence of the tone mapped video sequence. Extensive experimental results show that the developed spatio-temporal TMO (ST-TMO) solution yields higher coding performance than existing frame-by-frame TMO's, and compares favorably with state-of-the-art methods based on a fixed transfer function.