Lei Hsiung

selected publications

1. 

   AutoVP: An Automated Visual Prompting Framework and Benchmark

   Hsi-Ai Tsao*, Lei Hsiung*, Pin-Yu Chen, Sijia Liu, and Tsung-Yi Ho (* Equal Contribution)

   In Proceedings of the Twelfth International Conference on Learning Representations (ICLR) (2024)

   Abs arXiv Code

   Visual prompting (VP) is an emerging parameter-efficient fine-tuning approach to adapting pre-trained vision models to solve various downstream image-classification tasks. However, there has hitherto been little systematic study of the design space of VP and no clear benchmark for evaluating its performance. To bridge this gap, we propose AutoVP, an end-to-end expandable framework for automating VP design choices, along with 12 downstream image-classification tasks that can serve as a holistic VP-performance benchmark. Our design space covers 1) the joint optimization of the prompts; 2) the selection of pre-trained models, including image classifiers and text-image encoders; and 3) model output mapping strategies, including nonparametric and trainable label mapping. Our extensive experimental results show that AutoVP outperforms the best-known current VP methods by a substantial margin, having up to 6.7% improvement in accuracy; and attains a maximum performance increase of 27.5% compared to linear-probing (LP) baseline. AutoVP thus makes a two-fold contribution: serving both as an efficient tool for hyperparameter tuning on VP design choices, and as a comprehensive benchmark that can reasonably be expected to accelerate VP’s development.

2. 

   Towards Compositional Adversarial Robustness: Generalizing Adversarial Training to Composite Semantic Perturbations

   Lei Hsiung, Yun-Yun Tsai, Pin-Yu Chen, and Tsung-Yi Ho

   In Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR) (2023)

   Abs arXiv Code Demo

   Model robustness against adversarial examples of single perturbation type such as the \(\ell_p\)-norm has been widely studied, yet its generalization to more realistic scenarios involving multiple semantic perturbations and their composition remains largely unexplored. In this paper, we first propose a novel method for generating composite adversarial examples. Our method can find the optimal attack composition by utilizing component-wise projected gradient descent and automatic attack-order scheduling. We then propose generalized adversarial training (GAT) to extend model robustness from \(\ell_p\)-ball to composite semantic perturbations, such as the combination of Hue, Saturation, Brightness, Contrast, and Rotation. Results obtained using ImageNet and CIFAR-10 datasets indicate that GAT can be robust not only to all the tested types of a single attack, but also to any combination of such attacks. GAT also outperforms baseline \(\ell_∞\)-norm bounded adversarial training approaches by a significant margin.

3. 

   NCTV: Neural Clamping Toolkit and Visualization for Neural Network Calibration

   Lei Hsiung, Yung-Chen Tang, Pin-Yu Chen, and Tsung-Yi Ho

   In Proceedings of the 37th AAAI Conference on Artificial Intelligence Demo Track, AAAI (2023)

   Abs arXiv Code Demo

   With the advancement of deep learning technology, neural networks have demonstrated their excellent ability to provide accurate predictions in many tasks. However, a lack of consideration for neural network calibration will not gain trust from humans, even for high-accuracy models. In this regard, the gap between the confidence of the model’s predictions and the actual correctness likelihood must be bridged to derive a well-calibrated model. In this paper, we introduce the Neural Clamping Toolkit, the first open-source framework designed to help developers employ state-of-the-art model-agnostic calibrated models. Furthermore, we provide animations and interactive sections in the demonstration to familiarize researchers with calibration in neural networks. A Colab tutorial on utilizing our toolkit is also introduced.