  With the goal of recovering high-quality image content from its degraded
version, image restoration enjoys numerous applications, such as in
surveillance, computational photography, medical imaging, and remote sensing.
Recently, convolutional neural networks (CNNs) have achieved dramatic
improvements over conventional approaches for image restoration task. Existing
CNN-based methods typically operate either on full-resolution or on
progressively low-resolution representations. In the former case, spatially
precise but contextually less robust results are achieved, while in the latter
case, semantically reliable but spatially less accurate outputs are generated.
In this paper, we present a novel architecture with the collective goals of
maintaining spatially-precise high-resolution representations through the
entire network and receiving strong contextual information from the
low-resolution representations. The core of our approach is a multi-scale
residual block containing several key elements: (a) parallel multi-resolution
convolution streams for extracting multi-scale features, (b) information
exchange across the multi-resolution streams, (c) spatial and channel attention
mechanisms for capturing contextual information, and (d) attention based
multi-scale feature aggregation. In a nutshell, our approach learns an enriched
set of features that combines contextual information from multiple scales,
while simultaneously preserving the high-resolution spatial details. Extensive
experiments on five real image benchmark datasets demonstrate that our method,
named as MIRNet, achieves state-of-the-art results for a variety of image
processing tasks, including image denoising, super-resolution, and image
enhancement. The source code and pre-trained models are available at
https://github.com/swz30/MIRNet.
