PARFormer: Transformer-based Multi-Task Network for Pedestrian Attribute Recognition

Pedestrian attribute recognition (PAR) has received increasing attention because of its wide application in video surveillance and pedestrian analysis. Extracting robust feature representation is one of the key challenges in this task. The existing methods mainly use the convolutional neural network (CNN) as the backbone network to extract features. However, these methods mainly focus on small discriminative regions while ignoring the global perspective. To overcome these limitations, we propose a pure transformer-based multi-task PAR network named PARFormer, which includes four modules. In the feature extraction module, we build a transformer-based strong baseline for feature extraction, which achieves competitive results on several PAR benchmarks compared with the existing CNN-based baseline methods. In the feature processing module, we propose an effective data augmentation strategy named batch random mask (BRM) block to reinforce the attentive feature learning of random patches. Furthermore, we propose a multi-attribute center loss (MACL) to enhance the inter-attribute discriminability in the feature representations. In the viewpoint perception module, we explore the impact of viewpoints on pedestrian attributes, and propose a multi-view contrastive loss (MCVL) that enables the network to exploit the viewpoint information. In the attribute recognition module, we alleviate the negative-positive imbalance problem to generate the attribute predictions. The above modules interact and jointly learn a highly discriminative feature space, and supervise the generation of the final features. Extensive experimental results show that the proposed PARFormer network performs well compared to the state-of-the-art methods on several public datasets, including PETA, RAP, and PA100K. Code will be released at https://github.com/xwf199/PARFormer.

Lightweight Contrastive Protein Structure-Sequence Transformation

Pretrained protein structure models without labels are crucial foundations for the majority of protein downstream applications. The conventional structure pretraining methods follow the mature natural language pretraining methods such as denoised reconstruction and masked language modeling but usually destroy the real representation of spatial structures. The other common pretraining methods might predict a fixed set of predetermined object categories, where a restricted supervised manner limits their generality and usability as additional labeled data is required to specify any other protein concepts. In this work, we introduce a novel unsupervised protein structure representation pretraining with a robust protein language model. In particular, we first propose to leverage an existing pretrained language model to guide structure model learning through an unsupervised contrastive alignment. In addition, a self-supervised structure constraint is proposed to further learn the intrinsic information about the structures. With only light training data, the pretrained structure model can obtain better generalization ability. To quantitatively evaluate the proposed structure models, we design a series of rational evaluation methods, including internal tasks (e.g., contact map prediction, distribution alignment quality) and external/downstream tasks (e.g., protein design). The extensive experimental results conducted on multiple tasks and specific datasets demonstrate the superiority of the proposed sequence-structure transformation framework.