There is no settled universal 3D representation for geometry with many alternatives such as point clouds, meshes, implicit functions, and voxels to name a few. In this work, we present a new, compelling alternative for representing shapes using a sequence of cross-sectional closed loops. The loops across all planes form an organizational hierarchy which we leverage for autoregressive shape synthesis and editing. Loops are a non-local description of the underlying shape, as simple loop manipulations (such as shifts) result in significant structural changes to the geometry. This is in contrast to manipulating local primitives such as points in a point cloud or a triangle in a triangle mesh. We further demonstrate that loops are intuitive and natural primitive for analyzing and editing shapes, both computationally and for users.
translated by 谷歌翻译
A diffusion model learns to predict a vector field of gradients. We propose to apply chain rule on the learned gradients, and back-propagate the score of a diffusion model through the Jacobian of a differentiable renderer, which we instantiate to be a voxel radiance field. This setup aggregates 2D scores at multiple camera viewpoints into a 3D score, and repurposes a pretrained 2D model for 3D data generation. We identify a technical challenge of distribution mismatch that arises in this application, and propose a novel estimation mechanism to resolve it. We run our algorithm on several off-the-shelf diffusion image generative models, including the recently released Stable Diffusion trained on the large-scale LAION dataset.
translated by 谷歌翻译
自我训练在半监督学习中表现出巨大的潜力。它的核心思想是使用在标记数据上学习的模型来生成未标记样本的伪标签,然后自我教学。为了获得有效的监督,主动尝试通常会采用动量老师进行伪标签的预测,但要观察确认偏见问题,在这种情况下,错误的预测可能会提供错误的监督信号并在培训过程中积累。这种缺点的主要原因是,现行的自我训练框架充当以前的知识指导当前状态,因为老师仅与过去的学生更新。为了减轻这个问题,我们提出了一种新颖的自我训练策略,该策略使模型可以从未来学习。具体而言,在每个培训步骤中,我们都会首先优化学生(即,在不将其应用于模型权重的情况下缓存梯度),然后用虚拟未来的学生更新老师,最后要求老师为伪标记生产伪标签目前的学生作为指导。这样,我们设法提高了伪标签的质量,从而提高了性能。我们还通过深入(FST-D)和广泛(FST-W)窥视未来,开发了我们未来自我训练(FST)框架的两个变体。将无监督的域自适应语义分割和半监督语义分割的任务作为实例,我们在广泛的环境下实验表明了我们方法的有效性和优越性。代码将公开可用。
translated by 谷歌翻译
Making safe and human-like decisions is an essential capability of autonomous driving systems and learning-based behavior planning is a promising pathway toward this objective. Distinguished from existing learning-based methods that directly output decisions, this work introduces a predictive behavior planning framework that learns to predict and evaluate from human driving data. Concretely, a behavior generation module first produces a diverse set of candidate behaviors in the form of trajectory proposals. Then the proposed conditional motion prediction network is employed to forecast other agents' future trajectories conditioned on each trajectory proposal. Given the candidate plans and associated prediction results, we learn a scoring module to evaluate the plans using maximum entropy inverse reinforcement learning (IRL). We conduct comprehensive experiments to validate the proposed framework on a large-scale real-world urban driving dataset. The results reveal that the conditional prediction model is able to forecast multiple possible future trajectories given a candidate behavior and the prediction results are reactive to different plans. Moreover, the IRL-based scoring module can properly evaluate the trajectory proposals and select close-to-human ones. The proposed framework outperforms other baseline methods in terms of similarity to human driving trajectories. Moreover, we find that the conditional prediction model can improve both prediction and planning performance compared to the non-conditional model, and learning the scoring module is critical to correctly evaluating the candidate plans to align with human drivers.
translated by 谷歌翻译
The ubiquity of camera-embedded devices and the advances in deep learning have stimulated various intelligent mobile video applications. These applications often demand on-device processing of video streams to deliver real-time, high-quality services for privacy and robustness concerns. However, the performance of these applications is constrained by the raw video streams, which tend to be taken with small-aperture cameras of ubiquitous mobile platforms in dim light. Despite extensive low-light video enhancement solutions, they are unfit for deployment to mobile devices due to their complex models and and ignorance of system dynamics like energy budgets. In this paper, we propose AdaEnlight, an energy-aware low-light video stream enhancement system on mobile devices. It achieves real-time video enhancement with competitive visual quality while allowing runtime behavior adaptation to the platform-imposed dynamic energy budgets. We report extensive experiments on diverse datasets, scenarios, and platforms and demonstrate the superiority of AdaEnlight compared with state-of-the-art low-light image and video enhancement solutions.
translated by 谷歌翻译
随着强大图像编辑工具的广泛使用,图像篡改变得容易且现实。现有的图像法医方法仍然面临低准确性和鲁棒性的挑战。请注意,篡改区域通常是语义对象,在这封信中,我们提出了一个基于深层语义分割网络的有效图像篡改本地化方案。Consnext网络被用作编码器,以学习更好的功能表示。然后,Upernet解码器融合了多尺度功能,以实现更好的定位功能。采用合并损失和有效的数据扩展以确保有效的模型培训。广泛的实验结果证实,我们提出的方案的本地化性能优于其他最先进的方案。
translated by 谷歌翻译
由于互动交通参与者的随机性质和道路结构的复杂性,城市自动驾驶的决策是具有挑战性的。尽管基于强化的学习(RL)决策计划有望处理城市驾驶方案,但它的样本效率低和适应性差。在本文中,我们提出了Scene-Rep Transformer,以通过更好的场景表示编码和顺序预测潜在蒸馏来提高RL决策能力。具体而言,构建了多阶段变压器(MST)编码器,不仅对自我车辆及其邻居之间的相互作用意识进行建模,而且对代理商及其候选路线之间的意图意识。具有自我监督学习目标的连续潜伏变压器(SLT)用于将未来的预测信息提炼成潜在的场景表示,以减少勘探空间并加快训练的速度。基于软演员批评的最终决策模块(SAC)将来自场景rep变压器的精制潜在场景表示输入,并输出驾驶动作。该框架在五个挑战性的模拟城市场景中得到了验证,其性能通过成功率,安全性和效率方面的数据效率和性能的大幅度提高来定量表现出来。定性结果表明,我们的框架能够提取邻居代理人的意图,以帮助做出决策并提供更多多元化的驾驶行为。
translated by 谷歌翻译
了解人类情绪是智能机器人提供更好的人类机器人相互作用的关键能力。现有作品仅限于修剪视频级别的情感分类,无法找到与情感相对应的时间窗口。在本文中,我们介绍了一项新任务,称为视频中的时间情感本地化(TEL),该任务旨在检测人类的情感并将其相应的时间边界定位在带有校准字幕的未修剪视频中。与时间动作本地化相比,TEL提出了三个独特的挑战:1)情绪的时间动态极为多样; 2)情绪提示都嵌入了外观和复杂的情节中; 3)细粒度的时间注释是复杂且劳动密集型的。为了应对前两个挑战,我们提出了一个新颖的扩张上下文集成网络,该网络与粗细的两流体系结构。粗流通过建模多粒性时间上下文来捕获各种时间动力学。细流通过推理从粗流的多晶格时间上下文之间的依赖性来实现复杂的理解,并将它们自适应地集成到细粒度的视频段特征中。为了应对第三个挑战,我们引入了跨模式共识学习范式,该范式利用了对齐视频和字幕之间的固有语义共识,以实现弱监督的学习。我们为新的测试集提供了3,000个手动注释的时间边界,因此可以对TEL问题进行未来的研究进行定量评估。广泛的实验显示了我们方法对时间情绪定位的有效性。这项工作的存储库位于https://github.com/yyjmjc/temporal-emotion-localization-in-videos。
translated by 谷歌翻译
准确地预测占用和流量对于在复杂的交通情况下为自动驾驶汽车提供更好的安全性和互动至关重要。这项工作提出了Strajnet:一个多模式的SWIN变压框架,用于有效的场景占用和流动预测。我们采用Swin Transformer编码图像和相互作用感知运动表示形式,并提出一个交叉意识模块,以在不同的时间步长跨不同时间步骤将运动意识注入网格单元。然后通过颞膜金字塔解码器来解码流量和占用预测。所提出的方法在Waymo Open数据集基准中显示了竞争性预测准确性和其他评估指标。
translated by 谷歌翻译
相应地预测周围交通参与者的未来状态,并计划安全,平稳且符合社会的轨迹对于自动驾驶汽车至关重要。当前的自主驾驶系统有两个主要问题:预测模块通常与计划模块解耦,并且计划的成本功能很难指定和调整。为了解决这些问题,我们提出了一个端到端的可区分框架,该框架集成了预测和计划模块,并能够从数据中学习成本函数。具体而言,我们采用可区分的非线性优化器作为运动计划者,该运动计划将神经网络给出的周围剂的预测轨迹作为输入,并优化了自动驾驶汽车的轨迹,从而使框架中的所有操作都可以在框架中具有可观的成本,包括成本功能权重。提出的框架经过大规模的现实驾驶数据集进行了训练,以模仿整个驾驶场景中的人类驾驶轨迹,并在开环和闭环界面中进行了验证。开环测试结果表明,所提出的方法的表现优于各种指标的基线方法,并提供以计划为中心的预测结果,从而使计划模块能够输出接近人类的轨迹。在闭环测试中,提出的方法表明能够处理复杂的城市驾驶场景和鲁棒性,以抵抗模仿学习方法所遭受的分配转移。重要的是,我们发现计划和预测模块的联合培训比在开环和闭环测试中使用单独的训练有素的预测模块进行计划要比计划更好。此外,消融研究表明,框架中的可学习组件对于确保计划稳定性和性能至关重要。
translated by 谷歌翻译