GenAI4ELab/papercli-papers huggingface dataset:
Posterior Distillation Sampling
Authors: Juil Koo; Chanho Park; Minhyuk Sung
Venue: CVPR 2024 (main)

Abstract: We introduce Posterior Distillation Sampling (PDS) a novel optimization method for parametric image editing based on diffusion models. Existing optimization-based methods which leverage the powerful 2D prior of diffusion models to handle various parametric images have mainly focused on generation. Unlike generation editing requires a balance between conforming to the target attribute and preserving the identity of the source content. Recent 2D image editing methods have achieved this balance by leveraging the stochastic latent encoded in the generative process of diffusion models. To extend the editing capabilities of diffusion models shown in pixel space to parameter space we reformulate the 2D image editing method into an optimization form named PDS. PDS matches the stochastic latents of the source and the target enabling the sampling of targets in diverse parameter spaces that align with a desired attribute while maintaining the source's identity. We demonstrate that this optimization resembles running a generative process with the target attribute but aligning this process with the trajectory of the source's generative process. Extensive editing results in Neural Radiance Fields and Scalable Vector Graphics representations demonstrate that PDS is capable of sampling targets to fulfill the aforementioned balance across various parameter spaces.
HOISDF: Constraining 3D Hand-Object Pose Estimation with Global Signed Distance Fields
Authors: Haozhe Qi; Chen Zhao; Mathieu Salzmann; Alexander Mathis
Venue: CVPR 2024 (main)

Abstract: Human hands are highly articulated and versatile at handling objects. Jointly estimating the 3D poses of a hand and the object it manipulates from a monocular camera is challenging due to frequent occlusions. Thus existing methods often rely on intermediate 3D shape representations to increase performance. These representations are typically explicit such as 3D point clouds or meshes and thus provide information in the direct surroundings of the intermediate hand pose estimate. To address this we introduce HOISDF a Signed Distance Field (SDF) guided hand-object pose estimation network which jointly exploits hand and object SDFs to provide a global implicit representation over the complete reconstruction volume. Specifically the role of the SDFs is threefold: equip the visual encoder with implicit shape information help to encode hand-object interactions and guide the hand and object pose regression via SDF-based sampling and by augmenting the feature representations. We show that HOISDF achieves state-of-the-art results on hand-object pose estimation benchmarks (DexYCB and HO3Dv2). Code is available https://github.com/amathislab/HOISDF.
Enhancing Video Super-Resolution via Implicit Resampling-based Alignment
Authors: Kai Xu; Ziwei Yu; Xin Wang; Michael Bi Mi; Angela Yao
Venue: CVPR 2024 (main)

Abstract: In video super-resolution it is common to use a frame-wise alignment to support the propagation of information over time. The role of alignment is well-studied for low-level enhancement in video but existing works overlook a critical step -- resampling. We show through extensive experiments that for alignment to be effective the resampling should preserve the reference frequency spectrum while minimizing spatial distortions. However most existing works simply use a default choice of bilinear interpolation for resampling even though bilinear interpolation has a smoothing effect and hinders super-resolution. From these observations we propose an implicit resampling-based alignment. The sampling positions are encoded by a sinusoidal positional encoding while the value is estimated with a coordinate network and a window-based cross-attention. We show that bilinear interpolation inherently attenuates high-frequency information while an MLP-based coordinate network can approximate more frequencies. Experiments on synthetic and real-world datasets show that alignment with our proposed implicit resampling enhances the performance of state-of-the-art frameworks with minimal impact on both compute and parameters.
DiffPortrait3D: Controllable Diffusion for Zero-Shot Portrait View Synthesis
Authors: Yuming Gu; Hongyi Xu; You Xie; Guoxian Song; Yichun Shi; Di Chang; Jing Yang; Linjie Luo
Venue: CVPR 2024 (main)

Abstract: We present DiffPortrait3D a conditional diffusion model that is capable of synthesizing 3D-consistent photo-realistic novel views from as few as a single in-the-wild portrait. Specifically given a single RGB input we aim to synthesize plausible but consistent facial details rendered from novel camera views with retained both identity and facial expression. In lieu of time-consuming optimization and fine-tuning our zero-shot method generalizes well to arbitrary face portraits with unposed camera views extreme facial expressions and diverse artistic depictions. At its core we leverage the generative prior of 2D diffusion models pre-trained on large-scale image datasets as our rendering backbone while the denoising is guided with disentangled attentive control of appearance and camera pose. To achieve this we first inject the appearance context from the reference image into the self-attention layers of the frozen UNets. The rendering view is then manipulated with a novel conditional control module that interprets the camera pose by watching a condition image of a crossed subject from the same view. Furthermore we insert a trainable cross-view attention module to enhance view consistency which is further strengthened with a novel 3D-aware noise generation process during inference. We demonstrate state-of-the-art results both qualitatively and quantitatively on our challenging in-the-wild and multi-view benchmarks.
Rethinking Transformers Pre-training for Multi-Spectral Satellite Imagery
Authors: Mubashir Noman; Muzammal Naseer; Hisham Cholakkal; Rao Muhammad Anwer; Salman Khan; Fahad Shahbaz Khan
Venue: CVPR 2024 (main)

Abstract: Recent advances in unsupervised learning have demonstrated the ability of large vision models to achieve promising results on downstream tasks by pre-training on large amount of unlabelled data. Such pre-training techniques have also been explored recently in the remote sensing domain due to the availability of large amount of unlabelled data. Different from standard natural image datasets remote sensing data is acquired from various sensor technologies and exhibit diverse range of scale variations as well as modalities. Existing satellite image pre-training methods either ignore the scale information present in the remote sensing imagery or restrict themselves to use only a single type of data modality. In this paper we re-visit transformers pre-training and leverage multi-scale information that is effectively utilized with multiple modalities. Our proposed approach named SatMAE++ performs multi-scale pre-training and utilizes convolution based upsampling blocks to reconstruct the image at higher scales making it extensible to include more scales. Compared to existing works the proposed SatMAE++ with multi-scale pre-training is equally effective for both optical as well as multi-spectral imagery. Extensive experiments on six datasets reveal the merits of proposed contributions leading to state-of-the-art performance on all datasets. SatMAE++ achieves mean average precision (mAP) gain of 2.5% for multi-label classification task on BigEarthNet dataset.
LLM4SGG: Large Language Models for Weakly Supervised Scene Graph Generation
Authors: Kibum Kim; Kanghoon Yoon; Jaehyeong Jeon; Yeonjun In; Jinyoung Moon; Donghyun Kim; Chanyoung Park
Venue: CVPR 2024 (main)

Abstract: Weakly-Supervised Scene Graph Generation (WSSGG) research has recently emerged as an alternative to the fully-supervised approach that heavily relies on costly annotations. In this regard studies on WSSGG have utilized image captions to obtain unlocalized triplets while primarily focusing on grounding the unlocalized triplets over image regions. However they have overlooked the two issues involved in the triplet formation process from the captions: 1) Semantic over-simplification issue arises when extracting triplets from captions where fine-grained predicates in captions are undesirably converted into coarse-grained predicates resulting in a long-tailed predicate distribution and 2) Low-density scene graph issue arises when aligning the triplets in the caption with entity/predicate classes of interest where many triplets are discarded and not used in training leading to insufficient supervision. To tackle the two issues we propose a new approach i.e. Large Language Model for weakly-supervised SGG (LLM4SGG) where we mitigate the two issues by leveraging the LLM's in-depth understanding of language and reasoning ability during the extraction of triplets from captions and alignment of entity/predicate classes with target data. To further engage the LLM in these processes we adopt the idea of Chain-of-Thought and the in-context few-shot learning strategy. To validate the effectiveness of LLM4SGG we conduct extensive experiments on Visual Genome and GQA datasets showing significant improvements in both Recall@K and mean Recall@K compared to the state-of-the-art WSSGG methods. A further appeal is that LLM4SGG is data-efficient enabling effective model training with a small amount of training images.
Parameter Efficient Fine-tuning via Cross Block Orchestration for Segment Anything Model
Authors: Zelin Peng; Zhengqin Xu; Zhilin Zeng; Lingxi Xie; Qi Tian; Wei Shen
Venue: CVPR 2024 (main)

Abstract: Parameter-efficient fine-tuning (PEFT) is an effective methodology to unleash the potential of large foundation models in novel scenarios with limited training data. In the computer vision community PEFT has shown effectiveness in image classification but little research has studied its ability for image segmentation. Fine-tuning segmentation models usually require a heavier adjustment of parameters to align the proper projection directions in the parameter space for new scenarios. This raises a challenge to existing PEFT algorithms as they often inject a limited number of individual parameters into each block which prevents substantial adjustment of the projection direction of the parameter space due to the limitation of Hidden Markov Chain along blocks. In this paper we equip PEFT with a cross-block orchestration mechanism to enable the adaptation of the Segment Anything Model (SAM) to various downstream scenarios. We introduce a novel inter-block communication module which integrates a learnable relation matrix to facilitate communication among different coefficient sets of each PEFT block's parameter space. Moreover we propose an intra-block enhancement module which introduces a linear projection head whose weights are generated from a hyper-complex layer further enhancing the impact of the adjustment of projection directions on the entire parameter space. Extensive experiments on diverse benchmarks demonstrate that our proposed approach consistently improves the segmentation performance significantly on novel scenarios with only around 1K additional parameters.
Neural Directional Encoding for Efficient and Accurate View-Dependent Appearance Modeling
Authors: Liwen Wu; Sai Bi; Zexiang Xu; Fujun Luan; Kai Zhang; Iliyan Georgiev; Kalyan Sunkavalli; Ravi Ramamoorthi
Venue: CVPR 2024 (main)

Abstract: Novel-view synthesis of specular objects like shiny metals or glossy paints remains a significant challenge. Not only the glossy appearance but also global illumination effects including reflections of other objects in the environment are critical components to faithfully reproduce a scene. In this paper we present Neural Directional Encoding (NDE) a view-dependent appearance encoding of neural radiance fields (NeRF) for rendering specular objects. NDE transfers the concept of feature-grid-based spatial encoding to the angular domain significantly improving the ability to model high-frequency angular signals. In contrast to previous methods that use encoding functions with only angular input we additionally cone-trace spatial features to obtain a spatially varying directional encoding which addresses the challenging interreflection effects. Extensive experiments on both synthetic and real datasets show that a NeRF model with NDE (1) outperforms the state of the art on view synthesis of specular objects and (2) works with small networks to allow fast (real-time) inference. The source code is available at: https://github.com/lwwu2/nde
Masked and Shuffled Blind Spot Denoising for Real-World Images
Authors: Hamadi Chihaoui; Paolo Favaro
Venue: CVPR 2024 (main)

Abstract: We introduce a novel approach to single image denoising based on the Blind Spot Denoising principle which we call MAsked and SHuffled Blind Spot Denoising (MASH). We focus on the case of correlated noise which often plagues real images. MASH is the result of a careful analysis to determine the relationships between the level of blindness (masking) of the input and the (unknown) noise correlation. Moreover we introduce a shuffling technique to weaken the local correlation of noise which in turn yields an additional denoising performance improvement. We evaluate MASH via extensive experiments on real-world noisy image datasets. We demonstrate state-of-the-art results compared to existing self-supervised denoising methods.
Label Propagation for Zero-shot Classification with Vision-Language Models
Authors: Vladan Stojni?; Yannis Kalantidis; Giorgos Tolias
Venue: CVPR 2024 (main)

Abstract: Vision-Language Models (VLMs) have demonstrated impressive performance on zero-shot classification i.e. classification when provided merely with a list of class names. In this paper we tackle the case of zero-shot classification in the presence of unlabeled data. We leverage the graph structure of the unlabeled data and introduce ZLaP a method based on label propagation (LP) that utilizes geodesic distances for classification. We tailor LP to graphs containing both text and image features and further propose an efficient method for performing inductive inference based on a dual solution and a sparsification step. We perform extensive experiments to evaluate the effectiveness of our method on 14 common datasets and show that ZLaP outperforms the latest related works. Code: https://github.com/vladan-stojnic/ZLaP
DiffusionAvatars: Deferred Diffusion for High-fidelity 3D Head Avatars
Authors: Tobias Kirschstein; Simon Giebenhain; Matthias Nießner
Venue: CVPR 2024 (main)

Abstract: DiffusionAvatars synthesizes a high-fidelity 3D head avatar of a person offering intuitive control over both pose and expression. We propose a diffusion-based neural renderer that leverages generic 2D priors to produce compelling images of faces. For coarse guidance of the expression and head pose we render a neural parametric head model (NPHM) from the target viewpoint which acts as a proxy geometry of the person. Additionally to enhance the modeling of intricate facial expressions we condition DiffusionAvatars directly on the expression codes obtained from NPHM via cross-attention. Finally to synthesize consistent surface details across different viewpoints and expressions we rig learnable spatial features to the head's surface via TriPlane lookup in NPHM's canonical space. We train DiffusionAvatars on RGB videos and corresponding fitted NPHM meshes of a person and test the obtained avatars in both self-reenactment and animation scenarios. Our experiments demonstrate that DiffusionAvatars generates temporally consistent and visually appealing videos for novel poses and expressions of a person outperforming existing approaches.
Data-Free Quantization via Pseudo-label Filtering
Authors: Chunxiao Fan; Ziqi Wang; Dan Guo; Meng Wang
Venue: CVPR 2024 (main)

Abstract: Quantization for model compression can efficiently reduce the network complexity and storage requirement but the original training data is necessary to remedy the performance loss caused by quantization. The Data-Free Quantization (DFQ) methods have been proposed to handle the absence of original training data with synthetic data. However there are differences between the synthetic and original training data which affects the performance of the quantized network but none of the existing methods considers the differences. In this paper we propose an efficient data-free quantization via pseudo-label filtering which is the first to evaluate the synthetic data before quantization. We design a new metric for evaluating synthetic data using self-entropy which indicates the reliability of synthetic data. The synthetic data can be categorized with the metric into high- and low-reliable datasets for the following training process. Besides the multiple pseudo-labels are designed to label the synthetic data with different reliability which can provide valuable supervision information and avoid misleading training by low-reliable samples. Extensive experiments are implemented on several datasets including CIFAR-10 CIFAR-100 and ImageNet with various models. The experimental results show that our method can perform excellently and outperform existing methods in accuracy.
Revisiting Global Translation Estimation with Feature Tracks
Authors: Peilin Tao; Hainan Cui; Mengqi Rong; Shuhan Shen
Venue: CVPR 2024 (main)

Abstract: Global translation estimation is a highly challenging step in the global structure from motion (SfM) algorithm. Many existing methods depend solely on relative translations leading to inaccuracies in low parallax scenes and degradation under collinear camera motion. While recent approaches aim to address these issues by incorporating feature tracks into objective functions they are often sensitive to outliers. In this paper we first revisit global translation estimation methods with feature tracks and categorize them into explicit and implicit methods. Then we highlight the superiority of the objective function based on the cross-product distance metric and propose a novel explicit global translation estimation framework that integrates both relative translations and feature tracks as input. To enhance the accuracy of input observations we re-estimate relative translations with the coplanarity constraint of the epipolar plane and propose a simple yet effective strategy to select reliable feature tracks. Finally the effectiveness of our approach is demonstrated through experiments on urban image sequences and unordered Internet images showcasing its superior accuracy and robustness compared to many state-of-the-art techniques.
Open-Set Domain Adaptation for Semantic Segmentation
Authors: Seun-An Choe; Ah-Hyung Shin; Keon-Hee Park; Jinwoo Choi; Gyeong-Moon Park
Venue: CVPR 2024 (main)

Abstract: Unsupervised domain adaptation (UDA) for semantic segmentation aims to transfer the pixel-wise knowledge from the labeled source domain to the unlabeled target domain. However current UDA methods typically assume a shared label space between source and target limiting their applicability in real-world scenarios where novel categories may emerge in the target domain. In this paper we introduce Open-Set Domain Adaptation for Semantic Segmentation (OSDA-SS) for the first time where the target domain includes unknown classes. We identify two major problems in the OSDA-SS scenario as follows: 1) the existing UDA methods struggle to predict the exact boundary of the unknown classes and 2) they fail to accurately predict the shape of the unknown classes. To address these issues we propose Boundary and Unknown Shape-Aware open-set domain adaptation coined BUS. Our BUS can accurately discern the boundaries between known and unknown classes in a contrastive manner using a novel dilation-erosion-based contrastive loss. In addition we propose OpenReMix a new domain mixing augmentation method that guides our model to effectively learn domain and size-invariant features for improving the shape detection of the known and unknown classes. Through extensive experiments we demonstrate that our proposed BUS effectively detects unknown classes in the challenging OSDA-SS scenario compared to the previous methods by a large margin.
Generative Powers of Ten
Authors: Xiaojuan Wang; Janne Kontkanen; Brian Curless; Steven M. Seitz; Ira Kemelmacher-Shlizerman; Ben Mildenhall; Pratul Srinivasan; Dor Verbin; Aleksander Holynski
Venue: CVPR 2024 (main)

Abstract: We present a method that uses a text-to-image model to generate consistent content across multiple image scales enabling extreme semantic zooms into a scene e.g. ranging from a wide-angle landscape view of a forest to a macro shot of an insect sitting on one of the tree branches. We achieve this through a joint multi-scale diffusion sampling approach that encourages consistency across different scales while preserving the integrity of each individual sampling process. Since each generated scale is guided by a different text prompt our method enables deeper levels of zoom than traditional super-resolution methods that may struggle to create new contextual structure at vastly different scales. We compare our method qualitatively with alternative techniques in image super-resolution and outpainting and show that our method is most effective at generating consistent multi-scale content.
H-ViT: A Hierarchical Vision Transformer for Deformable Image Registration
Authors: Morteza Ghahremani; Mohammad Khateri; Bailiang Jian; Benedikt Wiestler; Ehsan Adeli; Christian Wachinger
Venue: CVPR 2024 (main)

Abstract: This paper introduces a novel top-down representation approach for deformable image registration which estimates the deformation field by capturing various short- and long-range flow features at different scale levels. As a Hierarchical Vision Transformer (H-ViT) we propose a dual self-attention and cross-attention mechanism that uses high-level features in the deformation field to represent low-level ones enabling information streams in the deformation field across all voxel patch embeddings irrespective of their spatial proximity. Since high-level features contain abstract flow patterns such patterns are expected to effectively contribute to the representation of the deformation field in lower scales. When the self-attention module utilizes within-scale short-range patterns for representation the cross-attention modules dynamically look for the key tokens across different scales to further interact with the local query voxel patches. Our method shows superior accuracy and visual quality over the state-of-the-art registration methods in five publicly available datasets highlighting a substantial enhancement in the performance of medical imaging registration. The project link is available at https://mogvision.github.io/hvit.
Sculpting Holistic 3D Representation in Contrastive Language-Image-3D Pre-training
Authors: Yipeng Gao; Zeyu Wang; Wei-Shi Zheng; Cihang Xie; Yuyin Zhou
Venue: CVPR 2024 (main)

Abstract: Contrastive learning has emerged as a promising paradigm for 3D open-world understanding i.e. aligning point cloud representation to image and text embedding space individually. In this paper we introduce MixCon3D a simple yet effective method aiming to sculpt holistic 3D representation in contrastive language-image-3D pre-training. In contrast to point cloud only we develop the 3D object-level representation from complementary perspectives e.g. multi-view rendered images with the point cloud. Then MixCon3D performs language-3D contrastive learning comprehensively depicting real-world 3D objects and bolstering text alignment. Additionally we pioneer the first thorough investigation of various training recipes for the 3D contrastive learning paradigm building a solid baseline with improved performance. Extensive experiments conducted on three representative benchmarks reveal that our method significantly improves over the baseline surpassing the previous state-of-the-art performance on the challenging 1156-category Objaverse-LVIS dataset by 5.7%. The versatility of MixCon3D is showcased in applications such as text-to-3D retrieval and point cloud captioning further evidencing its efficacy in diverse scenarios. The code is available at https://github.com/UCSC-VLAA/MixCon3D.