Face hallucination is a generative task to super-resolve the facial image with low resolution while human perception of face heav- ily relies on identity information. However, previous face hallucination approaches largely ignore facial identity recovery. This paper proposes Super-Identity Convolutional Neural Network (SICNN) to recover iden- tity information for generating faces closed to the real identity. Specif- ically, we define a super-identity loss to measure the identity difference between a hallucinated face and its corresponding high-resolution face within the hypersphere identity metric space. However, directly using this loss will lead to a Dynamic Domain Divergence problem, which is caused by the large margin between the high-resolution domain and the hallucination domain. To overcome this challenge, we present a domain- integrated training approach by constructing a robust identity metric for faces from these two domains. Extensive experimental evaluations demonstrate that the proposed SICNN achieves superior visual quality over the state-of-the-art methods on a challenging task to super-resolve 12×14 faces with an 8× upscaling factor. In addition, SICNN significant- ly improves the recognizability of ultra-low-resolution faces.
Leave a Reply