Blind Face Restoration (BFR), which involves converting low-quality facial images with unknown and varied degradation into high-quality counterparts, suffers from issues of sub-optimal restoration and over-correction due to inconsistent degradation levels. To rectify the above issue, inspired by the State Space model, especially the improved version Mamba’s enhanced long-range dependencies modeling ability and Stable Diffusion’s ability in integrating multi-modal prompts, we introduce a novel approach, Diff-Mamba Degradation Prediction Restoration (DM-DPR), to leverage the combination of a Mamba prompt generation framework with Stable Diffusion-based image restoration. Its core lies in two primary components: a Mamba-based multi-modal prompt generator that quantifies the degradation severity, generating corresponding textual and visual prompts, additionally with a multi-modal prompt driven Stable Diffusion process that adjusts restoration efforts based on the estimated degradation level. Derived from the CelebA-Test, we create degraded datasets exhibiting a wide range of degradation severity. Extensive experimental evaluations demonstrate that DM-DPR substantially surpasses existing state-of-the-art methods, thereby robustly establishing its enhanced capability to manage varying degrees of image degradation.

As the core operator of Transformers, Softmax Attention exhibits excellent global modeling capabilities. However, its quadratic complexity limits its applicability to vision tasks. In contrast, Linear Attention shares a similar formulation with Softmax Attention while achieving linear complexity, enabling efficient global information modeling. Nevertheless, Linear Attention suffers from a significant performance degradation compared to standard Softmax Attention. In this paper, we analyze the underlying causes of this issue based on the formulation of Linear Attention. We find that, unlike Softmax Attention, Linear Attention entirely disregards the magnitude information of the Query. This prevents the attention score distribution from dynamically adapting as the Query scales. As a result, despite its structural similarity to Softmax Attention, Linear Attention exhibits a significantly different attention score distribution. Based on this observation, we propose Magnitude-Aware Linear Attention (MALA), which modifies the computation of Linear Attention to fully incorporate the Query's magnitude. This adjustment allows MALA to generate an attention score distribution that closely resembles Softmax Attention while exhibiting a more well-balanced structure. We evaluate the effectiveness of MALA on multiple tasks, including image classification, object detection, instance segmentation, semantic segmentation, natural language processing, speech recognition, and image generation. Our MALA achieves strong results on all of these tasks. Code will be available at https://github.com/qhfan/MALA

Image restoration (IR) has made significant strides, evolving from basic pixel-wise restoration to more advanced techniques capable of handling diverse degradations. However, current all-in-one IR methods face challenges in effectively generalizing across complex real-world degradation scenarios. To address this challenge, we propose multi-task Restoration Mamba (ReMamba), a novel framework that leverages the power of state space models for long-sequence modeling to extract fine-grained degradation features from low-quality data. Guided by degradation-type prediction, which helps the model accurately identify and differentiate between various degradation types in the input, ReMamba employs prompt learning across both textual and visual modalities and enhances the restoration capabilities of downstream stable diffusion networks by injecting prompts as prior knowledge. Extensive experiments on both synthetic and real-world datasets, covering six distinct IR tasks, demonstrate the adaptability, generalizability, and robustness of ReMamba, highlighting its effectiveness in addressing a wide range of degradation types under challenging conditions.

Diffusion Transformer (DiT), a promising diffusion model for visual generation, demonstrates impressive performance but incurs significant computational overhead. Intriguingly, analysis of pre-trained DiT models reveals that global self-attention is often redundant, predominantly capturing local patterns—highlighting the potential for more efficient alternatives. In this paper, we revisit convolution as an alternative building block for constructing efficient and expressive diffusion models. However, naively replacing self-attention with convolution typically results in degraded performance. Our investigations attribute this performance gap to the higher channel redundancy in ConvNets compared to Transformers. To resolve this, we introduce a compact channel attention mechanism that promotes the activation of more diverse channels, thereby enhancing feature diversity. This leads to Diffusion ConvNet (DiCo), a family of diffusion models built entirely from standard ConvNet modules, offering strong generative performance with significant efficiency gains. On class-conditional ImageNet generation benchmarks, DiCo-XL achieves an FID of 2.05 at 256$\times$256 resolution and 2.53 at 512$\times$512, with a **2.7$\times$** and **3.1$\times$** speedup over DiT-XL/2, respectively. Furthermore, experimental results on MS-COCO demonstrate that the purely convolutional DiCo exhibits strong potential for text-to-image generation.

Despite substantial progress, all-in-one image restoration (IR) grapples with persistent challenges in handling intricate real-world degradations. This paper introduces MPerceiver: a novel multimodal prompt learning approach that harnesses Stable Diffusion (SD) priors to enhance adaptiveness, generalizability and fidelity for all-in-one im-age restoration. Specifically, we develop a dual-branch module to master two types of SD prompts: textual for holistic representation and visual for multiscale detail rep-resentation. Both prompts are dynamically adjusted by degradation predictions from the CLIP image encoder, en-abling adaptive responses to diverse unknown degradations. Moreover, a plug-in detail refinement module im-proves restoration fidelity via direct encoder-to-decoder in-formation transformation. To assess our method, MPer-ceiver is trained on 9 tasks for all-in-one IR and outper-forms state-of-the-art task-specific methods across many tasks. Post multitask pre-training, MPerceiver attains a generalized representation in low-level vision, exhibiting remarkable zero-shot and few-shot capabilities in unseen tasks. Extensive experiments on 16 IR tasks underscore the superiority of MPerceiver in terms of adaptiveness, gener-alizability and fidelity.

Unsupervised Domain Adaptation (UDA) can effectively address domain gap issues in real-world image Super-Resolution (SR) by accessing both the source and target data. Considering privacy policies or transmission restrictions of source data in practical scenarios, we propose a SOurce-free Domain Adaptation framework for image SR (SODA-SR) to address this issue, i.e., adapt a source-trained model to a target domain with only unlabeled target data. SODA-SR leverages the source-trained model to generate refined pseudo-labels for teacher-student learning. To better utilize pseudo-labels, we propose a novel wavelet-based augmentation method, named Wavelet Augmentation Transformer (WAT), which can be flexibly incorporated with existing networks, to implicitly produce useful augmented data. WAT learns low-frequency information of varying levels across diverse samples, which is aggregated efficiently via deformable attention. Furthermore, an uncertainty-aware self-training mechanism is proposed to improve the accuracy of pseudo-labels, with inaccurate predictions being rectified by uncertainty estimation. To acquire better SR results and avoid overfitting pseudo-labels, several regularization losses are proposed to constrain target LR and SR images in the frequency domain. Experiments show that without accessing source data, SODA-SR outperforms state-of-the-art UDA methods in both synthetic→real and real→real adaptation settings, and is not constrained by specific network architectures.

Image restoration (IR) in real-world scenarios presents significant challenges due to the lack of high-capacity models and comprehensive datasets. To tackle these issues, we present a dual strategy: GenIR, an innovative data curation pipeline, and DreamClear, a cutting-edge Diffusion Transformer (DiT)-based image restoration model. **GenIR**, our pioneering contribution, is a dual-prompt learning pipeline that overcomes the limitations of existing datasets, which typically comprise only a few thousand images and thus offer limited generalizability for larger models. GenIR streamlines the process into three stages: image-text pair construction, dual-prompt based fine-tuning, and data generation \& filtering. This approach circumvents the laborious data crawling process, ensuring copyright compliance and providing a cost-effective, privacy-safe solution for IR dataset construction. The result is a large-scale dataset of one million high-quality images. Our second contribution, **DreamClear**, is a DiT-based image restoration model. It utilizes the generative priors of text-to-image (T2I) diffusion models and the robust perceptual capabilities of multi-modal large language models (MLLMs) to achieve photorealistic restoration. To boost the model's adaptability to diverse real-world degradations, we introduce the Mixture of Adaptive Modulator (MoAM). It employs token-wise degradation priors to dynamically integrate various restoration experts, thereby expanding the range of degradations the model can address. Our exhaustive experiments confirm DreamClear's superior performance, underlining the efficacy of our dual strategy for real-world image restoration. Code and pre-trained models are available at: https://github.com/shallowdream204/DreamClear.