Zejia Fan

dblp:275/6782 · DBLP profile ↗
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11ranked-venue papers
3as first author
10since 2021 · last 2024
0000-0002-6205-3808ORCID · corroborated

Domains — the database's venue-derived domains; a paper can count in several

Graphics, computer vision, multimedia, augmented reality and games · 7 · 2 first-author · 6 since 2021Artificial intelligence and machine learning · 2 · 2 since 2021Systems, architecture and hardware · 2 · 1 first-author · 2 since 2021Applied, interdisciplinary, general and emerging computing · 2 · 1 since 2021Computer networks · 1 · 1 since 2021
YearPublicationVenuePosition
2024 S⁵Mars: Semi-Supervised Learning for Mars Semantic Segmentation
abstract
Deep learning has become a powerful tool for Mars exploration. Mars terrain semantic segmentation is an important Martian vision task, which is the base of rover autonomous planning and safe driving. However, there is a lack of sufficient detailed and high-confidence data annotations, which are exactly required by most deep learning methods to obtain a good model. To address this problem, we propose our solution from the perspective of joint data and method design. We first present a new dataset S5Mars for Semi-SuperviSed learning on Mars Semantic Segmentation, which contains 6K high-resolution images and is sparsely annotated based on confidence, ensuring the high quality of labels. Then to learn from this sparse data, we propose a semi-supervised learning (SSL) framework for Mars image semantic segmentation, to learn representations from limited labeled data. Different from the existing SSL methods which are mostly targeted at the Earth image data, our method takes into account Mars data characteristics. Specifically, we first investigate the impact of current widely used natural image augmentations on Mars images. Based on the analysis, we then proposed two novel and effective augmentations for SSL of Mars segmentation,AugINandSAM-Mix, which serve as strong augmentations to boost the model performance. Meanwhile, to fully leverage the unlabeled data, we introduce a soft-to-hard consistency learning strategy, learning from different targets based on prediction confidence. Experimental results show that our method can outperform state-of-the-art SSL approaches remarkably. Our proposed dataset is available at https://jhang2020.github.io/S5Mars.github.io/.
Jiahang Zhang 0001, Lilang Lin, Zejia Fan, Wenjing Wang 0001, Jiaying Liu 0001
IEEE Trans. Geosci. Remote. Sens.3
2024 Toward Real-World Super Resolution With Adaptive Self-Similarity Mining
abstract
Despite efforts to construct super-resolution (SR) training datasets with a wide range of degradation scenarios, existing supervised methods based on these datasets still struggle to consistently offer promising results due to the diversity of real-world degradation scenarios and the inherent complexity of model learning. Our work explores a new route: integrating the sample-adaptive property learned through image intrinsic self-similarity and the universal knowledge acquired from large-scale data. We achieve this by uniting internal learning and external learning by an unrolled optimization process. With the merits of both, the tuned fully-supervised SR models can be augmented to broadly handle the real-world degradation in a plug-and-play style. Furthermore, to promote the efficiency of combining internal/external learning, we apply an attention-based weight-updating method to guide the mining of self-similarity, and various data augmentations are adopted while applying the exponential moving average strategy. We conduct extensive experiments on real-world degraded images and our approach outperforms other methods in both qualitative and quantitative comparisons. Our project is available at: https://github.com/ZahraFan/AdaSSR/.
Zejia Fan, Wenhan Yang, Zongming Guo, Jiaying Liu 0001
IEEE Trans. Image Process.1
2023 Content-Adaptive Parallel Entropy Coding for End-to-End Image Compression
abstract
State-of-the-art entropy models, e.g. autoregressive context models, utilize spatial correlation among latent representations, leading to more accurate entropy estimation. However, this autoregressive design naturally results in serial decoding and the infeasibility of parallelization, which makes the decoding procedure slow and less practical. To address the issue, we propose a Content-Adaptive Parallel Entropy Model (CAPEM) that takes a two-pass context calculation with dynamically generated patterns. Our CAPEM relaxes the strict coding order while the dynamic context mechanism still promotes flexibility in capturing latent dependency. This design greatly improves the parallelism of the context model, leading to higher coding efficiency while maintaining the same rate-distortion performance. We test it on the widely used Kodak and CLIC image datasets. Experimental results show that the proposed model outperforms the recent works with less complexity.
Shujia Li, Dezhao Wang, Zejia Fan, Jiaying Liu 0001
ICIP3
2023 Semi-supervised Learning for Mars Imagery Classification and Segmentation
abstract
With the progress of Mars exploration, numerous Mars image data are being collected and need to be analyzed. However, due to the severe train-test gap and quality distortion of Martian data, the performance of existing computer vision models is unsatisfactory. In this article, we introduce a semi-supervised framework for machine vision on Mars and try to resolve two specific tasks: classification and segmentation. Contrastive learning is a powerful representation learning technique. However, there is too much information overlap between Martian data samples, leading to a contradiction between contrastive learning and Martian data. Our key idea is to reconcile this contradiction with the help of annotations and further take advantage of unlabeled data to improve performance. For classification, we propose to ignore inner-class pairs on labeled data as well as neglect negative pairs on unlabeled data, forming supervised inter-class contrastive learning and unsupervised similarity learning. For segmentation, we extend supervised inter-class contrastive learning into an element-wise mode and use online pseudo labels for supervision on unlabeled areas. Experimental results show that our learning strategies can improve the classification and segmentation models by a large margin and outperform state-of-the-art approaches.
Wenjing Wang 0001, Lilang Lin, Zejia Fan, Jiaying Liu 0001
ACM Trans. Multim. Comput. Commun. Appl.3
2022 Self-Learned Video Super-Resolution with Augmented Spatial and Temporal Context
abstract
Video super-resolution methods typically rely on paired training data, in which the low-resolution frames are usually synthetically generated under predetermined degradation conditions (e.g., Bicubic downsampling). However, in real applications, it is labor-consuming and expensive to obtain this kind of training data, which limits the practical performance of these methods. To address the issue and get rid of the synthetic paired data, in this paper, we make exploration in utilizing the internal self-similarity redundancy within the video to build a Self-Learned Video Super-Resolution (SLVSR) method, which only needs to be trained on the input testing video itself. We employ a series of data augmentation strategies to make full use of the spatial and temporal context of the target video clips. The idea is applied to two branches of mainstream SR methods: frame fusion and frame recurrence methods. Since the former takes advantage of the short-term temporal consistency and the latter of the long-term one, our method can satisfy different practical situations. The experimental results show the superiority of our proposed method, especially in addressing the video super-resolution problems in real applications.
Zejia Fan, Jiaying Liu 0001, Wenhan Yang, Zongming Guo
ICASSP1
2022 On the Connection between Local Attention and Dynamic Depth-wise Convolution
Qi Han 0007, Zejia Fan, Qi Dai 0001, Ming-Ming Cheng, Jiaying Liu 0001, Jingdong Wang 0001
ICLR2
2022 Critique of "MemXCT: Memory-Centric X-Ray CT Reconstruction With Massive Parallelization" by SCC Team From Peking University
abstract
Hidayetoluet al.(2019) proposed a novel memory-centric computation system, MemXCT. As a challenge at SC20, we reproduce the computational efficiency of MemXCT on our Azure cloud cluster. Our experiments evaluate the overall performance and the strong scalability with real datasets and verify part of the conclusions in the original article.
Zejia Fan, Zhewen Hao, Yueyang Pan, Pengcheng Xu 0005, Yuxuan Yan, Fangyuan Yang, Zhenxin Fu, Yun Liang 0001
IEEE Trans. Parallel Distributed Syst.1
2021 Conditional DETR for Fast Training Convergence
abstract
The recently-developed DETR approach applies the transformer encoder and decoder architecture to object detection and achieves promising performance. In this paper, we handle the critical issue, slow training convergence, and present a conditional cross-attention mechanism for fast DETR training. Our approach is motivated by that the cross-attention in DETR relies highly on the content embeddings for localizing the four extremities and predicting the box, which increases the need for high-quality content embeddings and thus the training difficulty.Our approach, named conditional DETR, learns a conditional spatial query from the decoder embedding for decoder multi-head cross-attention. The benefit is that through the conditional spatial query, each cross-attention head is able to attend to a band containing a distinct region, e.g., one object extremity or a region inside the object box. This narrows down the spatial range for localizing the distinct regions for object classification and box regression, thus relaxing the dependence on the content embeddings and easing the training. Empirical results show that conditional DETR converges 6.7× faster for the backbones R50 and R101 and 10× faster for stronger backbones DC5-R50 and DC5-R101. Code is available at https://github.com/Atten4Vis/ConditionalDETR.
Depu Meng, Xiaokang Chen, Zejia Fan, Houqiang Li, Yuhui Yuan, Jingdong Wang 0001
ICCV3
2021 Semi-Supervised Learning for Mars Imagery Classification
abstract
With the progress of Mars exploration, numerous Mars image data are collected and need to be analyzed. However, because of the imbalance and distortion in Mars data, the performance of existing classification models is unsatisfactory. In this paper, we design a new framework based on semi-supervised contrastive learning for Mars rover image classification. The redundancy of Mars data can disable the effectiveness of contrastive learning. To strip out problematic learning samples, we propose to ignore inner-class pairs on labeled data as well as neglect negative pairs on unlabeled data. Experimental results show that our learning strategies can improve the classification model by a large margin and outperform state-of-the-art methods.
Wenjing Wang 0001, Lilang Lin, Zejia Fan, Jiaying Liu 0001
ICIP3
2021 Critique of "Planetary Normal Mode Computation: Parallel Algorithms, Performance, and Reproducibility" by SCC Team From Peking University
abstract
Shi et al. (2018) proposed a highly parallel polynomial filtering eigensolver for the computation of planetary normal modes. As a challenge at the Student Cluster Competition in The International Conference for High Performance Computing, Networking, Storage and Analysis (SC19), we reproduce the computational efficiency of the polynomial filtering eigensolver on our Intel Xeon machine. We present the weak scalability, scaling of runtime with model size (in a fixed interval) and the strong scalability results in this report.
Yihua Cheng, Zejia Fan, Jing Mai, Yifan Wu 0005, Pengcheng Xu 0005, Yuxuan Yan, Zhenxin Fu, Yun Liang 0001
IEEE Trans. Parallel Distributed Syst.2
2020 Multi-class Skin Lesion Segmentation for Cutaneous T-cell Lymphomas on High-Resolution Clinical Images
Zihao Liu 0009, Haihao Pan, Zejia Fan, Yujie Wen, Tingting Jiang 0001, Ruiqin Xiong, Yang Wang 0048
MICCAI (6)4