Perceiving the environment for better and more efficient situational awareness is essential in applications such as wildlife surveillance, wildfire detection, crop irrigation, and building management. Energy-harvesting, intermittently-powered sensors have emerged as a zero maintenance solution for long-term environmental perception. However, these devices suffer from intermittent and varying energy supply, which presents three major challenges for executing perceptual tasks: (1) intelligently scaling computation in light of constrained resources and dynamic energy availability, (2) planning communication and sensing tasks, (3) and coordinating sensor nodes to increase the total perceptual range of the network. We propose an adaptive framework, AdaSens, which adapts the operations of intermittently-powered sensor nodes in a coordinated manner to cover as much as possible of the targeted scene, both spatially and temporally, under interruptions and constrained resources. We evaluate AdaSens on a real-world surveillance video dataset, VideoWeb, and show at least 16\% improvement on the coverage of the important frames compared with other methods.
In many intelligent systems, a network of agents collaboratively perceives the environment for better and more efficient situation awareness. As these agents often have limited resources, it could be greatly beneficial to identify the content overlapping among camera views from different agents and leverage it for reducing the processing, transmission and storage of redundant/unimportant video frames. This paper presents a consensus-based distributed multi-agent video fast-forwarding framework, named DMVF, that fast-forwards multi-view video streams collaboratively and adaptively. In our framework, each camera view is addressed by a reinforcement learning based fast-forwarding agent, which periodically chooses from multiple strategies to selectively process video frames and transmits the selected frames at adjustable paces. During every adaptation period, each agent communicates with a number of neighboring agents, evaluates the importance of the selected frames from itself and those from its neighbors, refines such evaluation together with other agents via a system-wide consensus algorithm, and uses such evaluation to decide their strategy for the next period. Compared with approaches in the literature on a real-world surveillance video dataset VideoWeb, our method significantly improves the coverage of important frames and also reduces the number of frames processed in the system.
For many intelligent applications with limited computation, communication, storage and energy resources, there is an imperative need of vision methods that could select an informative subset of the input video for efficient processing at or near real time. In the literature, there are two relevant groups of approaches: generating a "trailer" for a video or fast-forwarding while watching/processing the video. The first group is supported by video summarization techniques, which require processing of the entire video to select an important subset for showing to users. In the second group, current fast-forwarding methods depend on either manual control or automatic adaptation of playback speed, which often do not present an accurate representation and may still require processing of every frame. We introduce FastForwardNet (FFNet), a reinforcement learning agent that gets inspiration from video summarization and does fast-forwarding differently. It is an online framework that automatically fast-forwards a video and presents a representative subset of frames to users on the fly. It does not require processing the entire video but just the portion that is selected by the fast-forward agent, which makes the process very computationally efficient. The online nature of our proposed method also enables the users to begin fast-forwarding at any point of the video. Experiments on two real-world datasets demonstrate that our method can provide better representation of the input video (about 6%-20% improvement on coverage of important frames) with much less processing requirement (more than 80% reduction in the number of frames processed).
Instance segmentation is a promising yet challenging topic in computer vision. Recent approaches such as Mask R-CNN typically divide this problem into two parts -- a detection component and a mask generation branch, and mostly focus on the improvement of the detection part. We develop an approach that extends Mask R-CNN with five novel techniques for improving the mask generation branch and reducing the conflicts between the mask branch and the detection component in training. These five techniques are independent to each other and can be flexibly utilized in building various instance segmentation architectures for increasing the overall accuracy. We demonstrate the effectiveness of our approach with tests on the COCO dataset.
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