Biography

I am pursuing my M.S. degree in College of Control Science and Engineering, Zhejiang University, Hangzhou, China. My major research interests include computer vision and facial analysis.

Research and Interests

• Deep Learning
• Computer Vision
• Facial Analysis

Publications

• Xiangfang Zeng, Yusu Pan, Hao Zhang, Mengmeng Wang, Guanzhong Tian, and Yong Liu. Unpaired Salient Object Translation via Spatial Attention Prior. Neurocomputing, 2021.
  [BibTeX] [Abstract] [DOI] [PDF]

  With only set-level constraints, unpaired image translation is challenging in discovering the correct semantic-level correspondences between two domains. This limitation often results in false positives such as significantly changing color and appearance of the background during image translation. To address this limitation, we propose the Spatial Attention-Aware Generative Adversarial Network (SAAGAN), a novel approach to jointly learn salient object discovery and translation. Specifically, our generator consists of (1) spatial attention prediction branch and (2) image translation branch. For attention branch, we extract spatial attention prior from a pre-trained classification network to provide weak supervision for object discovery. The proposed attention loss can largely stabilize the training process of attention-guided generator. For translation branch, we revise classical adversarial loss for salient object translation. Such a discriminator only distinguish the distribution of the object between two domains. What is more, we propose a fake sample augmentation strategy to provide extra spatial information for discriminator. Our approach allows simultaneously locating the attention areas in each image and translating the related areas between two domains. Extensive experiments and evaluations show that our model can achieve more realistic mappings compared to state-of-the-art unpaired image translation methods.

  @article{zeng2021unpairedso,
  title = {Unpaired Salient Object Translation via Spatial Attention Prior},
  author = {Xiangfang Zeng and Yusu Pan and Hao Zhang and Mengmeng Wang and Guanzhong Tian and Yong Liu},
  year = 2021,
  journal = {Neurocomputing},
  doi = {10.1016/j.neucom.2020.05.105},
  abstract = {With only set-level constraints, unpaired image translation is challenging in discovering the correct semantic-level correspondences between two domains. This limitation often results in false positives such as significantly changing color and appearance of the background during image translation. To address this limitation, we propose the Spatial Attention-Aware Generative Adversarial Network (SAAGAN), a novel approach to jointly learn salient object discovery and translation. Specifically, our generator consists of (1) spatial attention prediction branch and (2) image translation branch. For attention branch, we extract spatial attention prior from a pre-trained classification network to provide weak supervision for object discovery. The proposed attention loss can largely stabilize the training process of attention-guided generator. For translation branch, we revise classical adversarial loss for salient object translation. Such a discriminator only distinguish the distribution of the object between two domains. What is more, we propose a fake sample augmentation strategy to provide extra spatial information for discriminator. Our approach allows simultaneously locating the attention areas in each image and translating the related areas between two domains. Extensive experiments and evaluations show that our model can achieve more realistic mappings compared to state-of-the-art unpaired image translation methods.}
  }

• Jun Chen, Yong Liu, Hao Zhang, Shengnan Hou, and Jian Yang. Propagating Asymptotic-Estimated Gradients for Low Bitwidth Quantized Neural Networks. IEEE Journal of Selected Topics in Signal Processing, 14:848–859, 2020.
  [BibTeX] [Abstract] [DOI] [arXiv] [PDF]

  The quantized neural networks (QNNs) can be useful for neural network acceleration and compression, but during the training process they pose a challenge: how to propagate the gradient of loss function through the graph flow with a derivative of 0 almost everywhere. In response to this non-differentiable situation, we propose a novel Asymptotic-Quantized Estimator (AQE) to estimate the gradient. In particular, during back-propagation, the graph that relates inputs to output remains smoothness and differentiability. At the end of training, the weights and activations have been quantized to low-precision because of the asymptotic behaviour of AQE. Meanwhile, we propose a M-bit Inputs and N-bit Weights Network (MINW-Net) trained by AQE, a quantized neural network with 1–3 bits weights and activations. In the inference phase, we can use XNOR or SHIFT operations instead of convolution operations to accelerate the MINW-Net. Our experiments on CIFAR datasets demonstrate that our AQE is well defined, and the QNNs with AQE perform better than that with Straight-Through Estimator (STE). For example, in the case of the same ConvNet that has 1-bit weights and activations, our MINW-Net with AQE can achieve a prediction accuracy 1.5% higher than the Binarized Neural Network (BNN) with STE. The MINW-Net, which is trained from scratch by AQE, can achieve comparable classification accuracy as 32-bit counterparts on CIFAR test sets. Extensive experimental results on ImageNet dataset show great superiority of the proposed AQE and our MINW-Net achieves comparable results with other state-of-the-art QNNs.

  @article{chen2020propagatingag,
  title = {Propagating Asymptotic-Estimated Gradients for Low Bitwidth Quantized Neural Networks},
  author = {Jun Chen and Yong Liu and Hao Zhang and Shengnan Hou and Jian Yang},
  year = 2020,
  journal = {IEEE Journal of Selected Topics in Signal Processing},
  volume = 14,
  pages = {848--859},
  doi = {https://doi.org/10.1109/JSTSP.2020.2966327},
  abstract = {The quantized neural networks (QNNs) can be useful for neural network acceleration and compression, but during the training process they pose a challenge: how to propagate the gradient of loss function through the graph flow with a derivative of 0 almost everywhere. In response to this non-differentiable situation, we propose a novel Asymptotic-Quantized Estimator (AQE) to estimate the gradient. In particular, during back-propagation, the graph that relates inputs to output remains smoothness and differentiability. At the end of training, the weights and activations have been quantized to low-precision because of the asymptotic behaviour of AQE. Meanwhile, we propose a M-bit Inputs and N-bit Weights Network (MINW-Net) trained by AQE, a quantized neural network with 1–3 bits weights and activations. In the inference phase, we can use XNOR or SHIFT operations instead of convolution operations to accelerate the MINW-Net. Our experiments on CIFAR datasets demonstrate that our AQE is well defined, and the QNNs with AQE perform better than that with Straight-Through Estimator (STE). For example, in the case of the same ConvNet that has 1-bit weights and activations, our MINW-Net with AQE can achieve a prediction accuracy 1.5% higher than the Binarized Neural Network (BNN) with STE. The MINW-Net, which is trained from scratch by AQE, can achieve comparable classification accuracy as 32-bit counterparts on CIFAR test sets. Extensive experimental results on ImageNet dataset show great superiority of the proposed AQE and our MINW-Net achieves comparable results with other state-of-the-art QNNs.},
  arxiv = {http://arxiv.org/pdf/2003.04296}
  }

• Hao Zhang, Mengmeng Wang, Yong Liu, and Yi Yuan. FDN: Feature Decoupling Network for Head Pose Estimation. In Proceedings of the 34th AAAI Conference on Artificial Intelligence (AAAI), 2020.
  [BibTeX] [Abstract] [DOI] [PDF]

  Head pose estimation from RGB images without depth information is a challenging task due to the loss of spatial information as well as large head pose variations in the wild. The performance of existing landmark-free methods remains unsatisfactory as the quality of estimated pose is inferior. In this paper, we propose a novel three-branch network architecture, termed as Feature Decoupling Network (FDN), a more powerful architecture for landmark-free head pose estimation from a single RGB image. In FDN, we first propose a feature decoupling (FD) module to explicitly learn the discriminative features for each pose angle by adaptively recalibrating its channel-wise responses. Besides, we introduce a cross-category center (CCC) loss to constrain the distribution of the latent variable subspaces and thus we can obtain more compact and distinct subspaces. Extensive experiments on both in-the-wild and controlled environment datasets demonstrate that the proposed method outperforms other state-of-the-art methods based on a single RGB image and behaves on par with approaches based on multimodal input resources.

  @inproceedings{zhang2020fdnfd,
  title = {FDN: Feature Decoupling Network for Head Pose Estimation},
  author = {Hao Zhang and Mengmeng Wang and Yong Liu and Yi Yuan},
  year = 2020,
  booktitle = {Proceedings of the 34th AAAI Conference on Artificial Intelligence (AAAI)},
  doi = {https://doi.org/10.1609/AAAI.V34I07.6974},
  abstract = {Head pose estimation from RGB images without depth information is a challenging task due to the loss of spatial information as well as large head pose variations in the wild. The performance of existing landmark-free methods remains unsatisfactory as the quality of estimated pose is inferior. In this paper, we propose a novel three-branch network architecture, termed as Feature Decoupling Network (FDN), a more powerful architecture for landmark-free head pose estimation from a single RGB image. In FDN, we first propose a feature decoupling (FD) module to explicitly learn the discriminative features for each pose angle by adaptively recalibrating its channel-wise responses. Besides, we introduce a cross-category center (CCC) loss to constrain the distribution of the latent variable subspaces and thus we can obtain more compact and distinct subspaces. Extensive experiments on both in-the-wild and controlled environment datasets demonstrate that the proposed method outperforms other state-of-the-art methods based on a single RGB image and behaves on par with approaches based on multimodal input resources.}
  }