Unsupervised Video Object Segmentation (VOS) aims at identifying the contours of primary foreground objects in videos without any prior knowledge. However, previous methods do not fully use spatial-temporal context and fail to tackle this challenging task in real-time. This motivates us to develop an efficient Long-Short Temporal Attention network (termed LSTA) for unsupervised VOS task from a holistic view. Specifically, LSTA consists of two dominant modules, i.e., Long Temporal Memory and Short Temporal Attention. The former captures the long-term global pixel relations of the past frames and the current frame, which models constantly present objects by encoding appearance pattern. Meanwhile, the latter reveals the short-term local pixel relations of one nearby frame and the current frame, which models moving objects by encoding motion pattern. To speedup the inference, the efficient projection and the locality-based sliding window are adopted to achieve nearly linear time complexity for the two light modules, respectively. Extensive empirical studies on several benchmarks have demonstrated promising performances of the proposed method with high efficiency.

无监督视频对象分割（VOS）旨在识别视频中主要前景对象的轮廓，但以往的方法没有充分利用时空上下文，并且无法在实时中处理这一具有挑战性的任务。因此，本文提出了一种高效的长短时序注意力网络（LSTA），从整体视角解决了无监督VOS任务。该网络由长时序记忆和短时序注意力两个主要模块组成，前者通过编码外观模式来捕获过去帧和当前帧的长期全局像素关系，后者通过编码动态模式来揭示附近帧和当前帧的短期局部像素关系。为了加快推理速度，采用了高效投影和基于局部性的滑动窗口，分别实现了两个轻量级模块的几乎线性时间复杂度。在几个基准测试中进行了大量实证研究，证明了所提方法具有高效的有希望的性能。

高效长短时注意力网络用于无监督视频目标分割