kf zheng

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Reading Notes of the Paper POSTER

Published Mar 13, 2024

POSTER

List of Datasets to Download

  1. RAF-DB

  2. FERPlus

  3. AffectNet 7 class & 8 class

Points

  • There are existing works that focus separately on inter-class similarity, intra-class discrepancy and scale sensitivity.

  • POSTER aims to solve the 3 problems as a whole.

  • techniques

    • 2 stream

      • image

        contains global features like cheeks, forehead, and tears drop that landmarks don’t involve

      • landmark

        reduce the effect from the image background and focus on the salient region

    • pyramid
    • cross-fusion
    • transformer

Motivation for designing a transformer-based cross-fusion block: let the 2 streams guide each other. the design alleviates inter-class similarity and intra-class discrepancy.

While the use of a pyramid is to reduce the effect of scale sensitivity.

  1. Deep Learning in FER. There are processes that have been made. From Region Attention Network(RAN) to ( idk what this is in detail) Deep Attentive Center Loss which can estimate the attention weight for the features for enhancing discrimination. And more.
  2. Facial Landmarks in FER. Used in Face recognition, tracking, and emotion recognition. Since the DL technique has been employed for facial landmark detection tasks, and many accurate detectors have been proposed. Researchers now can focus more on dealing with the landmark itself as a feature. Hence networks that take both images and landmarks as input were proposed. (3 works are mentioned, all ignore the correlations of facial landmarks and image features.)
  3. Vision Transformer. ViT, CrossViT

Methodology

  1. preprocesser(i call it)

    • Facial landmark detector

      Cunjian Chen. PyTorch Face Landmark: A fast and accurate facial landmark detector, 2021

    • Image backbone

      Jiankang Deng, Jia Guo, Niannan Xue, and Stefanos Zafeiriou. Arcface: Additive angular margin loss for deep face recognition. In Proceedings of the IEEE/CVF conference on computer vision and pattern recognition, pages 4690–4699, 2019

  2. cross-fusion transformer encoder

    • MSA
      • QKV encoding
      • double-head?
      • do the attention
    • norm and add and MLP and add
  3. pyramid

    By Conv1d in different kernel sizes and strides

Remaining Questions

  • What is the projection in AttentionBlock for? self.proj = nn.Linear(dim, dim)
  • Why is there no pos_embed in for x_lm in the ViT? Is it just because the landmark already contained position information?

POSTERV2

Difference

  1. Drop the image-to-landmark branch. That is, it performs transformer only on x_img.
  2. Drop Cross Fusion. Use global q from landmarks instead of local ones. Meanwhile do local attention too.
  3. Multi-scale by ir and lm.

Questions

  • After obtaining global attention features o1, o2, and o3, why use different ways to extract q, k, and v? (2*Conv2d, Conv2d, and none) well I guess it’s to make the o1, o2, and o3 to the same shape.