Predicting face attributes in the wild is challenging due to complex face
variations. We propose a novel deep learning framework for attribute prediction
in the wild. It cascades two CNNs, LNet and ANet, which are fine-tuned jointly
with attribute tags, but pre-trained differently. LNet is pre-trained by
massive general object categories for face localization, while ANet is
pre-trained by massive face identities for attribute prediction. This framework
not only outperforms the state-of-the-art with a large margin, but also reveals
valuable facts on learning face representation.
(1) It shows how the performances of face localization (LNet) and attribute
prediction (ANet) can be improved by different pre-training strategies.
(2) It reveals that although the filters of LNet are fine-tuned only with
image-level attribute tags, their response maps over entire images have strong
indication of face locations. This fact enables training LNet for face
localization with only image-level annotations, but without face bounding boxes
or landmarks, which are required by all attribute recognition works.
(3) It also demonstrates that the high-level hidden neurons of ANet
automatically discover semantic concepts after pre-training with massive face
identities, and such concepts are significantly enriched after fine-tuning with
attribute tags. Each attribute can be well explained with a sparse linear
combination of these concepts.

本文提出了一种深度学习框架，用于在野外预测面部属性，将 LNet 和 ANet 级联，且在预训练时分别使用大量通用对象类别和大量面部身份信息，最终得到优于现有技术的表现，并揭示了面部表示学习的有价值的事实。