arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1204.4476cs.CVcs.SYeess.SY
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动态模板跟踪与识别

Dynamic Template Tracking and Recognition

Center for Imaging Science Johns Hopkins University(成像科学中心约翰斯·霍普金斯大学)

Rizwan Chaudhry, Gregory Hager, Rene Vidal

AI总结:

提出使用线性动态系统建模非刚性物体的外观/运动时间演化,作为动态模板进行跟踪,并实现同时跟踪与识别。

摘要:

本文解决局部外观和运动随时间变化的非刚性物体跟踪问题。这类物体包括动态纹理(如蒸汽、火、烟、水等)以及关节物体(如执行各种动作的人)。我们使用线性动态系统(LDS)对物体外观/运动的时间演化进行建模。从样本视频中学习此类模型,并将其作为动态模板用于跟踪新视频中的物体。我们将当前帧中动态非刚性物体的跟踪问题视为在给定当前图像特征和前帧状态最佳估计下,物体位置和动态系统潜在状态的最大后验估计。我们方法的优势在于,通过使用先前训练的纹理动力学模型,可以预先指定场景中要跟踪的纹理类型。我们的框架自然地将常见的跟踪方法(如SSD和基于核的跟踪)从静态模板推广到动态模板。我们在合成和真实动态纹理示例上测试算法,并表明我们基于简单动力学的跟踪器性能与最先进方法相当甚至更优。由于我们的方法具有通用性且适用于任何图像特征,我们还将其应用于人体动作跟踪问题,构建了特定动作的光流跟踪器,在跟踪执行特定动作的人时性能优于最先进方法。最后,由于我们的方法是生成式的,我们可以使用针对不同纹理或动作类别预先训练的跟踪器,同时跟踪和识别视频中的纹理或动作。

英文摘要:

In this paper we address the problem of tracking non-rigid objects whose local appearance and motion changes as a function of time. This class of objects includes dynamic textures such as steam, fire, smoke, water, etc., as well as articulated objects such as humans performing various actions. We model the temporal evolution of the object's appearance/motion using a Linear Dynamical System (LDS). We learn such models from sample videos and use them as dynamic templates for tracking objects in novel videos. We pose the problem of tracking a dynamic non-rigid object in the current frame as a maximum a-posteriori estimate of the location of the object and the latent state of the dynamical system, given the current image features and the best estimate of the state in the previous frame. The advantage of our approach is that we can specify a-priori the type of texture to be tracked in the scene by using previously trained models for the dynamics of these textures. Our framework naturally generalizes common tracking methods such as SSD and kernel-based tracking from static templates to dynamic templates. We test our algorithm on synthetic as well as real examples of dynamic textures and show that our simple dynamics-based trackers perform at par if not better than the state-of-the-art. Since our approach is general and applicable to any image feature, we also apply it to the problem of human action tracking and build action-specific optical flow trackers that perform better than the state-of-the-art when tracking a human performing a particular action. Finally, since our approach is generative, we can use a-priori trained trackers for different texture or action classes to simultaneously track and recognize the texture or action in the video.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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