The existing face image super-resolution (FSR) algorithms usually train a
specific model for a specific low input resolution for optimal results. By
contrast, we explore in this work a unified framework that is trained once and
then used to super-resolve input face images of varied low resolutions. For
that purpose, we propose a novel neural network architecture that is composed
of three anchor auto-encoders, one feature weight regressor and a final image
decoder. The three anchor auto-encoders are meant for optimal FSR for three
pre-defined low input resolutions, or named anchor resolutions, respectively.
An input face image of an arbitrary low resolution is firstly up-scaled to the
target resolution by bi-cubic interpolation and then fed to the three
auto-encoders in parallel. The three encoded anchor features are then fused
with weights determined by the feature weight regressor. At last, the fused
feature is sent to the final image decoder to derive the super-resolution
result. As shown by experiments, the proposed algorithm achieves robust and
state-of-the-art performance over a wide range of low input resolutions by a
single framework. Code and models will be made available after the publication
of this work.

提出了一种使用统一框架进行人脸图像超分辨率的算法，该算法采用三个自编码器、一个特征权重回归器和一个最终的图像解码器作为神经网络结构，可以对多种不同低分辨率的输入图像进行超分辨率处理，实现了领先水平的性能表现。