2 J. Yu et al.
African, Asian, and Indian. Similarly, gender is another aspect of face recognition
datasets imbalance, dataset mainly consists of male faces. To solve these prob-
lems, many efforts on face recognition aim to tackle the class imbalance problem
on training data. For example, in prior-DNN era, Zhang et al. [38] proposed a
cost-sensitive learning framework to reduce misclassification rate of face identi-
fication. To correct the skew of separating hyperplanes of SVM on imbalanced
data, Liu et al. [20] proposed Margin-Based Adaptive Fuzzy SVM that obtains
a lower generalization error bound. In the DNN era, face recognition models are
trained on large-scale face datasets with highly-imbalanced class distribution.
Range Loss [37] learns a robust face representation that makes the most use
of every training sample. To mitigate the impact of insufficient class samples,
center-based feature transfer learning [35] and large margin feature augmenta-
tion [33] are proposed to augment features of minority identities and equalize
class distribution. Besides, the FRVT 2019 [12] shows the demographic bias of
over 100 face recognition algorithms. To uncover deep learning bias, Alexander
et al. [3] developed an algorithm to mitigate the hidden biases within training
data. Wang et al. [32] proposed a domain adaptation network to reduce racial
bias in face recognition. They recently extended their work using reinforcement
learning to find optimal margins of additive angular margin based loss functions
for different races [31].
In this paper, we present a face recognition method to achieve fair face recog-
nition. Giving an image with a loosely cropped face roughly in the center, the
first thing we need to do is obtaining the face from the image. As a fundamental
step for various facial applications, like face alignment [28], parsing [7], recogni-
tion [34], and verification [9], face detection achieves great progress inspired by
deep convolutional neural network (CNN). Previous state-of-the-art face detec-
tors can be roughly divided into two categories. The first one is mainly based on
the Region Proposal Network (RPN) adopted in Faster RCNN [25] and employs
two stage detection schemes [29]. RPN is trained end-to-end and generates high
quality region proposals which are further refined by Fast R-CNN detector. The
other one is Single Shot Detector (SSD) [19] based one-stage methods, which
get rid of RPN, and directly predict the bounding boxes and confidence [8]. Re-
cently, one-stage face detection framework has attracted more attention due to
its higher inference efficiency and straightforward system deployment. We test
multiple face detectors, such as MTCNN [36], Retinaface [10], DSFD [17], and
propose an improved method based on DSFD.
After obtaining the face from image, as diversity between different attributes
is very large, a series of face preprocessing methods are used to reduce bias and
improve accuracy at the same time. For instance, we use a data re-sampling
method to balance the data distribution by under-sampling the majority class.
Train data enhancement and test time augmentation are used for obtaining im-
proved accuracy. Then train data would be used to train face recognition models,
trained mo dels are used to extract features of test data. Next, by calculating the
cosine similarity between two feature vectors, confidence scores of test data would
be generated, which indicate the degree two faces belong to the same person.