Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
92
result(s) for
"Zhou, Shangchen"
Sort by:
Exploiting Diffusion Prior for Real-World Image Super-Resolution
by
Yue, Zongsheng
,
Zhou, Shangchen
,
Loy, Chen Change
in
Computer vision
,
Controllability
,
Image resolution
2024
We present a novel approach to leverage prior knowledge encapsulated in pre-trained text-to-image diffusion models for blind super-resolution. Specifically, by employing our time-aware encoder, we can achieve promising restoration results without altering the pre-trained synthesis model, thereby preserving the generative prior and minimizing training cost. To remedy the loss of fidelity caused by the inherent stochasticity of diffusion models, we employ a controllable feature wrapping module that allows users to balance quality and fidelity by simply adjusting a scalar value during the inference process. Moreover, we develop a progressive aggregation sampling strategy to overcome the fixed-size constraints of pre-trained diffusion models, enabling adaptation to resolutions of any size. A comprehensive evaluation of our method using both synthetic and real-world benchmarks demonstrates its superiority over current state-of-the-art approaches. Code and models are available at https://github.com/IceClear/StableSR.
Journal Article
LaVie: High-Quality Video Generation with Cascaded Latent Diffusion Models
by
He, Yinan
,
Yu, Jiashuo
,
Dai, Bo
in
Artificial Intelligence
,
Computer Imaging
,
Computer Science
2025
This work aims to learn a high-quality text-to-video (T2V) generative model by leveraging a pre-trained text-to-image (T2I) model as a basis. It is a highly desirable yet challenging task to simultaneously (a) accomplish the synthesis of visually realistic and temporally coherent videos while (b) preserving the strong creative generation nature of the pre-trained T2I model. To this end, we propose
LaVie
, an integrated video generation framework that operates on cascaded video latent diffusion models, comprising a base T2V model, a temporal interpolation model, and a video super-resolution model. Our key insights are two-fold: (1) We reveal that the incorporation of simple temporal self-attentions, coupled with rotary positional encoding, adequately captures the temporal correlations inherent in video data. (2) Additionally, we validate that the process of joint image-video fine-tuning plays a pivotal role in producing high-quality and creative outcomes. To enhance the performance of LaVie, we contribute a comprehensive and diverse video dataset named
Vimeo25M
, consisting of 25 million text-video pairs that prioritize quality, diversity, and aesthetic appeal. Extensive experiments demonstrate that LaVie achieves state-of-the-art performance both quantitatively and qualitatively. Furthermore, we showcase the versatility of pre-trained LaVie models in various long video generation and personalized video synthesis applications. Project page:
https://github.com/Vchitect/LaVie/
.
Journal Article
The Economics of CSI300 Stock Index Futures in China
2020
Chinese financial markets play an ever more pertinent role within the global economic. In this thesis, we investigate empirically the efficiency and functioning of the Chinese Security Index 300 (CSI300) index future. While CSI300 index futures market is a relatively new market, it has attracted huge trading volume and liquidity as there is no other financial derivatives markets in China and the short-selling in the stock market is difficult. Therefore, it is important and informative to examine both the hedging effectiveness and price discovery ability of CSI300 stock index futures. This thesis presents one of the first attempts in empirically investigate the market efficiency and hedging effective of the Chinese stock index futures from 2012 to 2018. In particular, chapter 2 studies the hedging effectiveness of CSI300 index futures with both static and dynamic hedging methods. The results show that CSI300 stock index futures is an effective hedging instrument, and in general the performance of dynamic models are better than static models. In chapter 3, we analyze the price discovery contribution of CSI300 index futures market in the context of six relevant hypothesis and three empirical measures (PT/GG, IS, and MIS methods). The price discovery performance of Chinese stock index futures is found to be consistent with the other mature markets, indicating that new information that affects the fundamental value is reflected more quickly in the CSI300 index futures markets. Finally, using the efficient market hypothesis and unbiasedness hypothesis, CSI300 index futures is also found to be informational efficient in chapter 4. The market is partially efficient and the futures price is a constant risk unbiased predictor for the subsequent spot price in the long run. Different from previous literature which focus on the CSI300 futures and spot market, this thesis utilizes various data frequency and futures with different maturity to address the empirical issues regarding the functioning of CSI300 futures market. In addition, this thesis is the first study to the impact of regulation reforms in 2015 (when Chinese regulators strictly tightened the rules on trading stock index futures) on CSI300 index futures market. Finally, the performance of the CSI300 index futures market has been compared and evaluated with other more mature index futures markets around the globe. The findings of this thesis have important implications to market regulators and participants in developing more effective investment and regulatory strategies.
Dissertation
Gradual recovery based occluded digit images recognition
2019
Recent research shows that auto-encoder is suitable to model a variation which varies smoothly. In this paper, we attempt to utilize auto-encoder to recognize partially occluded digit images with gradual recovery. We propose a new variation of auto-encoder, namely the “generalized auto-encoder”, and construct stacked generalized auto-encoders (SGAE) for the problem of occluded digit images recovery and recognition. Rather than recovering the occlusion directly, the degree of occlusion is regarded as a continuous variable, and the recovery task is regarded as a gradual process. We divide the whole task into multiple intermediate recovery procedures, and assign each procedure to one generalized auto-encoder, thus handling the recovery problem gradually. Based on the encouraging recovery results, the occluded digit images can be recognized well. The results demonstrate that gradual recovery outperforms direct recovery of the occluded region. Moreover, the main application in this paper is occluded digit images recognition, though, the proposed framework can be generalized to other problems easily and nicely. Extensive experiments are designed to verify our settings and show the effectiveness, extendibility and generalizability of the method.
Journal Article
LN3DIFF++: Scalable Latent Neural Fields Diffusion for Speedy 3D Generation
by
Chen, Yongwei
,
Chen Change Loy
,
Hong, Fangzhou
in
Diffusion rate
,
Harnesses
,
Image reconstruction
2025
The field of neural rendering has witnessed significant progress with advancements in generative models and differentiable rendering techniques. Though 2D diffusion has achieved success, a unified 3D diffusion pipeline remains unsettled. This paper introduces a novel framework called LN3Diff++ to address this gap and enable fast, high-quality, and generic conditional 3D generation. Our approach harnesses a 3D-aware architecture and variational autoencoder (VAE) to encode the input image into a structured, compact, and 3D latent space. The latent is decoded by a transformer-based decoder into a high-capacity 3D neural field. Through training a diffusion model on this 3D-aware latent space, our method achieves state-of-the-art performance on ShapeNet for 3D generation and demonstrates superior performance in monocular 3D reconstruction and conditional 3D generation across various datasets. Moreover, it surpasses existing 3D diffusion methods in terms of inference speed, requiring no per-instance optimization. Our proposed LN3Diff presents a significant advancement in 3D generative modeling and holds promise for various applications in 3D vision and graphics tasks.
Bokeh Diffusion: Defocus Blur Control in Text-to-Image Diffusion Models
2026
Recent advances in large-scale text-to-image models have revolutionized creative fields by generating visually captivating outputs from textual prompts; however, while traditional photography offers precise control over camera settings to shape visual aesthetics - such as depth-of-field via aperture - current diffusion models typically rely on prompt engineering to mimic such effects. This approach often results in crude approximations and inadvertently alters the scene content. In this work, we propose Bokeh Diffusion, a scene-consistent bokeh control framework that explicitly conditions a diffusion model on a physical defocus blur parameter. To overcome the scarcity of paired real-world images captured under different camera settings, we introduce a hybrid training pipeline that aligns in-the-wild images with synthetic blur augmentations, providing diverse scenes and subjects as well as supervision to learn the separation of image content from lens blur. Central to our framework is our grounded self-attention mechanism, trained on image pairs with different bokeh levels of the same scene, which enables blur strength to be adjusted in both directions while preserving the underlying scene. Extensive experiments demonstrate that our approach enables flexible, lens-like blur control, supports downstream applications such as real image editing via inversion, and generalizes effectively across both Stable Diffusion and FLUX architectures.
Linear Image Generation by Synthesizing Exposure Brackets
2026
The life of a photo begins with photons striking the sensor, whose signals are passed through a sophisticated image signal processing (ISP) pipeline to produce a display-referred image. However, such images are no longer faithful to the incident light, being compressed in dynamic range and stylized by subjective preferences. In contrast, RAW images record direct sensor signals before non-linear tone mapping. After camera response curve correction and demosaicing, they can be converted into linear images, which are scene-referred representations that directly reflect true irradiance and are invariant to sensor-specific factors. Since image sensors have better dynamic range and bit depth, linear images contain richer information than display-referred ones, leaving users more room for editing during post-processing. Despite this advantage, current generative models mainly synthesize display-referred images, which inherently limits downstream editing. In this paper, we address the task of text-to-linear-image generation: synthesizing a high-quality, scene-referred linear image that preserves full dynamic range, conditioned on a text prompt, for professional post-processing. Generating linear images is challenging, as pre-trained VAEs in latent diffusion models struggle to simultaneously preserve extreme highlights and shadows due to the higher dynamic range and bit depth. To this end, we represent a linear image as a sequence of exposure brackets, each capturing a specific portion of the dynamic range, and propose a DiT-based flow-matching architecture for text-conditioned exposure bracket generation. We further demonstrate downstream applications including text-guided linear image editing and structure-conditioned generation via ControlNet.
MatAnyone 2: Scaling Video Matting via a Learned Quality Evaluator
by
Zhou, Shangchen
,
Tao, Qingyi
,
Yang, Peiqing
in
Annotations
,
Datasets
,
Frames (data processing)
2026
Video matting remains limited by the scale and realism of existing datasets. While leveraging segmentation data can enhance semantic stability, the lack of effective boundary supervision often leads to segmentation-like mattes lacking fine details. To this end, we introduce a learned Matting Quality Evaluator (MQE) that assesses semantic and boundary quality of alpha mattes without ground truth. It produces a pixel-wise evaluation map that identifies reliable and erroneous regions, enabling fine-grained quality assessment. The MQE scales up video matting in two ways: (1) as an online matting-quality feedback during training to suppress erroneous regions, providing comprehensive supervision, and (2) as an offline selection module for data curation, improving annotation quality by combining the strengths of leading video and image matting models. This process allows us to build a large-scale real-world video matting dataset, VMReal, containing 28K clips and 2.4M frames. To handle large appearance variations in long videos, we introduce a reference-frame training strategy that incorporates long-range frames beyond the local window for effective training. Our MatAnyone 2 achieves state-of-the-art performance on both synthetic and real-world benchmarks, surpassing prior methods across all metrics.
Precise Object and Effect Removal with Adaptive Target-Aware Attention
2026
Object removal requires eliminating not only the target object but also its associated visual effects such as shadows and reflections. However, diffusion-based inpainting and removal methods often introduce artifacts, hallucinate contents, alter background, and struggle to remove object effects accurately. To address these challenges, we propose ObjectClear, a novel framework that decouples foreground removal from background reconstruction via an adaptive target-aware attention mechanism. This design empowers the model to precisely localize and remove both objects and their effects while maintaining high background fidelity. Moreover, the learned attention maps are leveraged for an attention-guided fusion strategy during inference, further enhancing visual consistency. To facilitate the training and evaluation, we construct OBER, a large-scale dataset for OBject-Effect Removal, which provides paired images with and without object-effects, along with precise masks for both objects and their effects. The dataset comprises high-quality captured and simulated data, covering diverse objects, effects, and complex multi-object scenes. Extensive experiments demonstrate that ObjectClear outperforms prior methods, achieving superior object-effect removal quality and background fidelity, especially in challenging scenarios.
Zoom-IQA: Image Quality Assessment with Reliable Region-Aware Reasoning
2026
Image Quality Assessment (IQA) is a long-standing problem in computer vision. Previous methods typically focus on predicting numerical scores without explanation or providing low-level descriptions lacking precise scores. Recent reasoning-based vision language models (VLMs) have shown strong potential for IQA by jointly generating quality descriptions and scores. However, existing VLM-based IQA methods often suffer from unreliable reasoning due to their limited capability of integrating visual and textual cues. In this work, we introduce Zoom-IQA, a VLM-based IQA model to explicitly emulate key cognitive behaviors: uncertainty awareness, region reasoning, and iterative refinement. Specifically, we present a two-stage training pipeline: 1) supervised fine-tuning (SFT) on our Grounded-Rationale-IQA (GR-IQA) dataset to teach the model to ground its assessments in key regions, and 2) reinforcement learning (RL) for dynamic policy exploration, stabilized by our KL-Coverage regularizer to prevent reasoning and scoring diversity collapse, with a Progressive Re-sampling Strategy for mitigating annotation bias. Extensive experiments show that Zoom-IQA achieves improved robustness, explainability, and generalization. The application to downstream tasks, such as image restoration, further demonstrates the effectiveness of Zoom-IQA.