Joint Super-Resolution and Inverse Tone-Mapping: A Feature Decomposition Aggregation Network and A New Benchmark

Joint Super-Resolution and Inverse Tone-Mapping (joint SR-ITM) aims to increase the resolution and dynamic range of low-resolution and standard dynamic range images.Recent methods mainly resort to image decomposition techniques with the multi-branch network architecture.However, the rigid decomposition employed by these methods largely restricts their power on diverse images.To exploit its potential power, in this paper, we generalize the decomposition mechanism from the image domain to the broader feature domain. To this end, we propose a lightweight Feature Decomposition Aggregation Network (FDAN). In particular, we design a Feature Decomposition Block (FDB), which can achieve learnable separation of feature details and contrasts.By cascading FDBs, we can build up a Hierarchical Feature Decomposition Group for powerful multi-level feature decomposition.Moreover, we collect a new benchmark dataset for joint SR-ITM, \ie, SRITM-4K, which is large-scale and provides versatile scenarios for sufficient model training and evaluation.Experimental results on two benchmark datasets demonstrate that our FDAN is efficient and outperforms previous methods on joint SR-ITM.Our code and dataset will be publicly released.