← Search

Liqun Chen

25 accepted papers

2025

A Physics-Informed Blur Learning Framework for Imaging Systems

CVPR 2025poster

Accurate blur estimation is essential for high-performance imaging across various applications. Blur is typically represented by the point spread function (PSF). In this paper, we propose a physics-informed PSF learning framework for imaging systems, consisting of a simple calibration followed by a…

2025

DriveEditor: A Unified 3D Information-Guided Framework for Controllable Object Editing in Driving Scenes

AAAI 2025technical

Vision-centric autonomous driving systems require diverse data for robust training and evaluation, which can be augmented by manipulating object positions and appearances within existing scene captures. While recent advancements in diffusion models have shown promise in video editing, their applicat…

2025

High-dimension Prototype is a Better Incremental Object Detection Learner

ICLR 2025poster

Incremental object detection (IOD), surpassing simple classification, requires the simultaneous overcoming of catastrophic forgetting in both recognition and localization tasks, primarily due to the significantly higher feature space complexity. Integrating Knowledge Distillation (KD) would mitigate…

Cited by 0SourcePDFScholar
2024

Make Lossy Compression Meaningful for Low-Light Images

AAAI 2024technical

Low-light images frequently occur due to unavoidable environmental influences or technical limitations, such as insufficient lighting or limited exposure time. To achieve better visibility for visual perception, low-light image enhancement is usually adopted. Besides, lossy image compression is vita…

2023

Understanding and Constructing Latent Modality Structures in Multi-Modal Representation Learning

CVPR 2023poster

Contrastive loss has been increasingly used in learning representations from multiple modalities. In the limit, the nature of the contrastive loss encourages modalities to exactly match each other in the latent space. Yet it remains an open question how the modality alignment affects the downstream…

Cited by 54SourcePDFScholar
2022

Vision-Language Pre-Training With Triple Contrastive Learning

CVPR 2022poster

Vision-language representation learning largely benefits from image-text alignment through contrastive losses (e.g., InfoNCE loss). The success of this alignment strategy is attributed to its capability in maximizing the mutual information (MI) between an image and its matched text. However, simply…

Cited by 351PDFcodeScholar
2022

Why do We Need Large Batchsizes in Contrastive Learning? A Gradient-Bias Perspective

NeurIPS 2022accept

Contrastive learning (CL) has been the de facto technique for self-supervised representation learning (SSL), with impressive empirical success such as multi-modal representation learning. However, traditional CL loss only considers negative samples from a minibatch, which could cause biased gradient…

Cited by 40SourcePDFScholar
2021

Contextualized Perturbation for Textual Adversarial Attack

NAACL 2021long

Adversarial examples expose the vulnerabilities of natural language processing (NLP) models, and can be used to evaluate and improve their robustness. Existing techniques of generating such examples are typically driven by local heuristic rules that are agnostic to the context, often resulting in un…

2021

SpanPredict: Extraction of Predictive Document Spans with Neural Attention

NAACL 2021long

In many natural language processing applications, identifying predictive text can be as important as the predictions themselves. When predicting medical diagnoses, for example, identifying predictive content in clinical notes not only enhances interpretability, but also allows unknown, descriptive (…

Cited by 5SourcePDFScholar
2021

Wasserstein Contrastive Representation Distillation

CVPR 2021poster

The primary goal of knowledge distillation (KD) is to encapsulate the information of a model learned from a teacher network into a student network, with the latter being more compact than the former. Existing work, e.g., using Kullback-Leibler divergence for distillation, may fail to capture importa…

Cited by 128PDFScholar
2020

Graph Optimal Transport for Cross-Domain Alignment

ICML 2020poster

Cross-domain alignment between two sets of entities (e.g., objects in an image, words in a sentence) is fundamental to both computer vision and natural language processing. Existing methods mainly focus on designing advanced attention mechanisms to simulate soft alignment, where no training signals…

2019

Improving Sequence-to-Sequence Learning via Optimal Transport

ICLR 2019poster

Sequence-to-sequence models are commonly trained via maximum likelihood estimation (MLE). However, standard MLE training considers a word-level objective, predicting the next word given the previous ground-truth partial sentence. This procedure focuses on modeling local syntactic patterns, and may f…

Cited by 110SourcePDFScholar
2019

Improving Textual Network Learning with Variational Homophilic Embeddings

NeurIPS 2019poster

The performance of many network learning applications crucially hinges on the success of network embedding algorithms, which aim to encode rich network information into low-dimensional vertex-based vector representations. This paper considers a novel variational formulation of network embeddings, wi…

2019

Variational Annealing of GANs: A Langevin Perspective

ICML 2019oral

The generative adversarial network (GAN) has received considerable attention recently as a model for data synthesis, without an explicit specification of a likelihood function. There has been commensurate interest in leveraging likelihood estimates to improve GAN training. To enrich the understandin…

Cited by 23SourcePDFScholar
2018

Adversarial Text Generation via Feature-Mover's Distance

NeurIPS 2018poster

Generative adversarial networks (GANs) have achieved significant success in generating real-valued data. However, the discrete nature of text hinders the application of GAN to text-generation tasks. Instead of using the standard GAN objective, we propose to improve text-generation GAN via a novel ap…

2018

Chi-square Generative Adversarial Network

ICML 2018oral

To assess the difference between real and synthetic data, Generative Adversarial Networks (GANs) are trained using a distribution discrepancy measure. Three widely employed measures are information-theoretic divergences, integral probability metrics, and Hilbert space discrepancy metrics. We elucida…

2018

Continuous-Time Flows for Efficient Inference and Density Estimation

ICML 2018oral

Two fundamental problems in unsupervised learning are efficient inference for latent-variable models and robust density estimation based on large amounts of unlabeled data. Algorithms for the two tasks, such as normalizing flows and generative adversarial networks (GANs), are often developed indepen…

2018

Symmetric Variational Autoencoder and Connections to Adversarial Learning

AISTATS 2018poster

A new form of the variational autoencoder (VAE) is proposed, based on the symmetric Kullback- Leibler divergence. It is demonstrated that learn- ing of the resulting symmetric VAE (sVAE) has close connections to previously developed adversarial-learning methods. This relationship helps unify the pre…

Cited by 0SourcePDFScholar
2018

Variational Inference and Model Selection with Generalized Evidence Bounds

ICML 2018oral

Recent advances on the scalability and flexibility of variational inference have made it successful at unravelling hidden patterns in complex data. In this work we propose a new variational bound formulation, yielding an estimator that extends beyond the conventional variational bound. It naturally…

2017

ALICE: Towards Understanding Adversarial Learning for Joint Distribution Matching

NeurIPS 2017poster

We investigate the non-identifiability issues associated with bidirectional adversarial training for joint distribution matching. Within a framework of conditional entropy, we propose both adversarial and non-adversarial approaches to learn desirable matched joint distributions for unsupervised and…

2017

Adversarial Symmetric Variational Autoencoder

NeurIPS 2017poster

A new form of variational autoencoder (VAE) is developed, in which the joint distribution of data and codes is considered in two (symmetric) forms: (i) from observed data fed through the encoder to yield codes, and (ii) from latent codes drawn from a simple prior and propagated through the decoder t…

Cited by 100SourcePDFScholar
2017

Triangle Generative Adversarial Networks

NeurIPS 2017poster

A Triangle Generative Adversarial Network ($\Delta$-GAN) is developed for semi-supervised cross-domain joint distribution matching, where the training data consists of samples from each domain, and supervision of domain correspondence is provided by only a few paired samples. $\Delta$-GAN consists o…

Cited by 168SourcePDFScholar