To reproduce the success of text-to-image (T2I) generation, recent works in text-to-video (T2V) generation employ large-scale text-video dataset for fine-tuning. However, such paradigm is computationally expensive. Humans have the amazing ability to learn new visual concepts from just one single exemplar. We hereby study a new T2V generation problem$\unicode{x2014}$One-Shot Video Generation, where only a single text-video pair is presented for training an open-domain T2V generator. Intuitively, we propose to adapt the T2I diffusion model pretrained on massive image data for T2V generation. We make two key observations: 1) T2I models are able to generate images that align well with the verb terms; 2) extending T2I models to generate multiple images concurrently exhibits surprisingly good content consistency. To further learn continuous motion, we propose Tune-A-Video with a tailored Sparse-Causal Attention, which generates videos from text prompts via an efficient one-shot tuning of pretrained T2I diffusion models. Tune-A-Video is capable of producing temporally-coherent videos over various applications such as change of subject or background, attribute editing, style transfer, demonstrating the versatility and effectiveness of our method.

Vision-Language Pre-Training (VLP) has shown promising capabilities to align image and text pairs, facilitating a broad variety of cross-modal learning tasks. However, we observe that VLP models often lack the visual grounding/localization capability which is critical for many downstream tasks such as visual reasoning. In this work, we propose a novel Position-guided Text Prompt (PTP) paradigm to enhance the visual grounding ability of cross-modal models trained with VLP. Specifically, in the VLP phase, PTP divides the image into $N\times N$ blocks, and identifies the objects in each block through the widely used object detector in VLP. It then reformulates the visual grounding task into a fill-in-the-blank problem given a PTP by encouraging the model to predict the objects in the given blocks or regress the blocks of a given object, e.g. filling `P" or ``O" in aPTP ``The block P has a O". This mechanism improves the visual grounding capability of VLP models and thus helps them better handle various downstream tasks. By introducing PTP into several state-of-the-art VLP frameworks, we observe consistently significant improvements across representative cross-modal learning model architectures and several benchmarks, e.g. zero-shot Flickr30K Retrieval (+4.8 in average recall@1) for ViLT \cite{vilt} baseline, and COCO Captioning (+5.3 in CIDEr) for SOTA BLIP \cite{blip} baseline. Moreover, PTP achieves comparable results with object-detector based methods, and much faster inference speed since PTP discards its object detector for inference while the later cannot. Our code and pre-trained weight will be released at \url{https://github.com/sail-sg/ptp}.

To build Video Question Answering (VideoQA) systems capable of assisting humans in daily activities, seeking answers from long-form videos with diverse and complex events is a must. Existing multi-modal VQA models achieve promising performance on images or short video clips, especially with the recent success of large-scale multi-modal pre-training. However, when extending these methods to long-form videos, new challenges arise. On the one hand, using a dense video sampling strategy is computationally prohibitive. On the other hand, methods relying on sparse sampling struggle in scenarios where multi-event and multi-granularity visual reasoning are required. In this work, we introduce a new model named Multi-modal Iterative Spatial-temporal Transformer (MIST) to better adapt pre-trained models for long-form VideoQA. Specifically, MIST decomposes traditional dense spatial-temporal self-attention into cascaded segment and region selection modules that adaptively select frames and image regions that are closely relevant to the question itself. Visual concepts at different granularities are then processed efficiently through an attention module. In addition, MIST iteratively conducts selection and attention over multiple layers to support reasoning over multiple events. The experimental results on four VideoQA datasets, including AGQA, NExT-QA, STAR, and Env-QA, show that MIST achieves state-of-the-art performance and is superior at computation efficiency and interpretability.

Recent advances in generative adversarial networks (GANs) have demonstrated the capabilities of generating stunning photo-realistic portrait images. While some prior works have applied such image GANs to unconditional 2D portrait video generation and static 3D portrait synthesis, there are few works successfully extending GANs for generating 3D-aware portrait videos. In this work, we propose PV3D, the first generative framework that can synthesize multi-view consistent portrait videos. Specifically, our method extends the recent static 3D-aware image GAN to the video domain by generalizing the 3D implicit neural representation to model the spatio-temporal space. To introduce motion dynamics to the generation process, we develop a motion generator by stacking multiple motion layers to generate motion features via modulated convolution. To alleviate motion ambiguities caused by camera/human motions, we propose a simple yet effective camera condition strategy for PV3D, enabling both temporal and multi-view consistent video generation. Moreover, PV3D introduces two discriminators for regularizing the spatial and temporal domains to ensure the plausibility of the generated portrait videos. These elaborated designs enable PV3D to generate 3D-aware motion-plausible portrait videos with high-quality appearance and geometry, significantly outperforming prior works. As a result, PV3D is able to support many downstream applications such as animating static portraits and view-consistent video motion editing. Code and models will be released at https://showlab.github.io/pv3d.

Vector-Quantized (VQ-based) generative models usually consist of two basic components, i.e., VQ tokenizers and generative transformers. Prior research focuses on improving the reconstruction fidelity of VQ tokenizers but rarely examines how the improvement in reconstruction affects the generation ability of generative transformers. In this paper, we surprisingly find that improving the reconstruction fidelity of VQ tokenizers does not necessarily improve the generation. Instead, learning to compress semantic features within VQ tokenizers significantly improves generative transformers' ability to capture textures and structures. We thus highlight two competing objectives of VQ tokenizers for image synthesis: semantic compression and details preservation. Different from previous work that only pursues better details preservation, we propose Semantic-Quantized GAN (SeQ-GAN) with two learning phases to balance the two objectives. In the first phase, we propose a semantic-enhanced perceptual loss for better semantic compression. In the second phase, we fix the encoder and codebook, but enhance and finetune the decoder to achieve better details preservation. The proposed SeQ-GAN greatly improves VQ-based generative models and surpasses the GAN and Diffusion Models on both unconditional and conditional image generation. Our SeQ-GAN (364M) achieves Frechet Inception Distance (FID) of 6.25 and Inception Score (IS) of 140.9 on 256x256 ImageNet generation, a remarkable improvement over VIT-VQGAN (714M), which obtains 11.2 FID and 97.2 IS.

Our education system comprises a series of curricula. For example, when we learn mathematics at school, we learn in order from addition, to multiplication, and later to integration. Delineating a curriculum for teaching either a human or a machine shares the underlying goal of maximizing the positive knowledge transfer from early to later tasks and minimizing forgetting of the early tasks. Here, we exhaustively surveyed the effect of curricula on existing continual learning algorithms in the class-incremental setting, where algorithms must learn classes one at a time from a continuous stream of data. We observed that across a breadth of possible class orders (curricula), curricula influence the retention of information and that this effect is not just a product of stochasticity. Further, as a primary effort toward automated curriculum design, we proposed a method capable of designing and ranking effective curricula based on inter-class feature similarities. We compared the predicted curricula against empirically determined effectual curricula and observed significant overlaps between the two. To support the study of a curriculum designer, we conducted a series of human psychophysics experiments and contributed a new Continual Learning benchmark in object recognition. We assessed the degree of agreement in effective curricula between humans and machines. Surprisingly, our curriculum designer successfully predicts an optimal set of curricula that is effective for human learning. There are many considerations in curriculum design, such as timely student feedback and learning with multiple modalities. Our study is the first attempt to set a standard framework for the community to tackle the problem of teaching humans and machines to learn to learn continuously.

VQA是一项雄心勃勃的任务，旨在回答任何与图像有关的问题。但是，实际上，由于用户的需求不断更新，并且该系统必须实施新功能，因此很难为所有人构建这样的系统。因此，持续学习（CL）能力是开发高级VQA系统的必要条件。最近，先锋工作将一个VQA数据集分为不相交的答案集以研究此主题。但是，VQA上的CL不仅涉及标签集的扩展（新答案集）。在将VQA系统部署到新环境（新的视觉场景）以及如何回答需要新功能的问题（新问题类型）时，研究如何回答问题至关重要。因此，我们提出了Clove，这是一个在视觉问题答案上连续学习的基准，其中包含上述两个CL方案的场景和功能收入设置。在方法论方面，VQA和分类的CL之间的主要区别在于，前者还涉及扩大和防止忘记推理机制，而后者则集中在班级表示上。因此，我们提出了一种为CL上量身定制的基于无数据的基于Real-DATA的基于VQA上的方法，称为场景图作为符号重播的提示。它使用一段场景图作为提示，它可以重播伪场景图，以表示过去的图像以及相关的QA对。还提出了一个统一的VQA模型来利用当前和重播数据来增强其质量检查能力。最后，实验结果揭示了丁香的挑战，并证明了我们方法的有效性。数据集和代码将在https://github.com/showlab/clvqa上找到。

Open-World实例细分（OWIS）旨在从图像中分割类不足的实例，该图像具有广泛的现实应用程序，例如自主驾驶。大多数现有方法遵循两阶段的管道：首先执行类不足的检测，然后再进行特定于类的掩模分段。相比之下，本文提出了一个单阶段框架，以直接为每个实例生成掩码。另外，实例掩码注释在现有数据集中可能很吵。为了克服这个问题，我们引入了新的正规化损失。具体而言，我们首先训练一个额外的分支来执行预测前景区域的辅助任务（即属于任何对象实例的区域），然后鼓励辅助分支的预测与实例掩码的预测一致。关键的见解是，这种交叉任务一致性损失可以充当误差校正机制，以打击注释中的错误。此外，我们发现所提出的跨任务一致性损失可以应用于图像，而无需任何注释，将自己借给了半监督的学习方法。通过广泛的实验，我们证明了所提出的方法可以在完全监督和半监督的设置中获得令人印象深刻的结果。与SOTA方法相比，所提出的方法将$ ap_ {100} $得分提高了4.75 \％\％\％\ rightarrow $ uvo设置和4.05 \％\％\％\％\％\％\ rightarrow $ uvo设置。在半监督学习的情况下，我们的模型仅使用30 \％标记的数据学习，甚至超过了其完全监督的数据，并具有5​​0 \％标记的数据。该代码将很快发布。

在本报告中，我们建议针对四个EGO4D挑战任务，包括自然语言查询（NLQ），MOMMER QUERY（MQ），对象状态变更分类（OSCC），以及PNR定位（PNR）。尤其是，我们将最近发布的EGO4D数据集\ cite {grauman2021ego4d}从预处理数据集，预处理目标和开发集中从egecentric vlp中提升。基于上述三个设计，我们开发了一个验证的视频语言模型，该模型能够将其以自我为中心的视频文本表示或仅视频表示形式转移到几个视频下游任务中。我们的Egentric VLP在NLQ上实现10.46r@1&iou @0.3，MQ上的10.33地图，OSCC上的74％ACC，PNR上的0.67秒错误。该代码可在https://github.com/showlab/egovlp上找到。

在本报告中，我们为Epic-kitchens-100多实体检索（miR）挑战提出了一个基于视频的预处理（VLP）解决方案\ cite {kevin202222222egovlp}。尤其是，我们将最近发布的EGO4D数据集\ cite {grauman2021ego4d}从预处理数据集，预处理目标和开发集中从egecentric vlp中提升。基于上述三个设计，我们开发了一个预验证的视频语言模型，该模型能够将其自我为中心的视频文本表示为mir基准。此外，我们设计了一种自适应多构度最大损失，以有效地微调模型并为可靠的推理配备双重效果技术。我们最好的单个模型在挑战测试集上获得了强劲的性能，其中47.39％的地图和61.44％的NDCG。该代码可在https://github.com/showlab/egovlp上找到。