This paper proposes a motion-based region growing segmentation scheme for the object-based video coding, which segments an image into homogeneous regions characterized by a coherent motion. It adopts a block matching ...This paper proposes a motion-based region growing segmentation scheme for the object-based video coding, which segments an image into homogeneous regions characterized by a coherent motion. It adopts a block matching algorithm to estimate motion vectors and uses morphological tools such as open-close by reconstruction and the region-growing version of the watershed algorithm for spatial segmentation to improve the temporal segmentation. In order to determine the reliable motion vectors, this paper also proposes a change detection algorithm and a multi-candidate pro- screening motion estimation method. Preliminary simulation results demonstrate that the proposed scheme is feasible. The main advantage of the scheme is its low computational load.展开更多
In this study, we report a spindle-like micromotor. This device, which is fabricated using a one-step electrospinning method, consists of biodegradable polycaprolactone and an anionic surfactant. Intriguingly, not onl...In this study, we report a spindle-like micromotor. This device, which is fabricated using a one-step electrospinning method, consists of biodegradable polycaprolactone and an anionic surfactant. Intriguingly, not only can the resulting micromotor move autonomously on the surface of water for a long period of time （-40 min） due to the Marangoni effect, but it also exhibits a pH sensing behavior due to variations in the surface tension caused by the release of surfactant under different pH conditions. More interestingly, we reveal that the motion-based pH sensing property is size-dependent, with smaller structures exhibiting a higher sensitivity. In addition, since polycaprolactone is a biode- gradable material, the micromotor described in this study can be easily degraded in solution. Hence, features such as one-step fabrication, motion readout, and biodegradability render this micromotor an attractive candidate for sensing algplications.展开更多
Sustaining awkward postures and overexertion are common factors in construction industry that result in work-related injuries of workers. To address there safety and health issues, conventional observational methods o...Sustaining awkward postures and overexertion are common factors in construction industry that result in work-related injuries of workers. To address there safety and health issues, conventional observational methods on the external causes are tedious and subjective, while the direct measurement on the internal causes is intrusive leading to productivity reduction. Therefore, it is essential to construct an effective approach that maps the external and internal causes to realize the non-intrusive identification of safety and health risks. This research proposes a theoretical method to analyze the postures tracked by videos with biomechanical models. Through the biomechanical skeleton representation of human body, the workload and joint torques are rapidly and accurately evaluated based on the rotation angles of joints. The method is then demonstrated by two case studies about(1) plastering and(2) carrying. The experiment results illustrate the changing intramuscular torques across the construction activities in essence, validating the proposed approach to be effective in theory.展开更多
为解决视频拼接过程中配准效率低、实时性差的问题,提出基于网格运动统计的视频图像快速拼接算法。将改进的快速旋转不变性特征(Oriented FAST and Rotated BRIEF,ORB)和网格运动统计(Grid-based Motion Statistics,GMS)算法相结合,优...为解决视频拼接过程中配准效率低、实时性差的问题,提出基于网格运动统计的视频图像快速拼接算法。将改进的快速旋转不变性特征(Oriented FAST and Rotated BRIEF,ORB)和网格运动统计(Grid-based Motion Statistics,GMS)算法相结合,优化图像金字塔尺度空间结构,引入快速视网膜关键点算法对特征点进行二进制描述,并采用最佳缝合线和拉普拉斯融合算法对多路视频进行拼接。经实验结果分析,提高了视频拼接的鲁棒性和实时性。与传统算法相比,图像配准速度在亮度、旋转、尺度方面分别提高28.7%、35.2%、33.9%,准确率分别提升21.6%、10.6%、9.9%。展开更多
文摘This paper proposes a motion-based region growing segmentation scheme for the object-based video coding, which segments an image into homogeneous regions characterized by a coherent motion. It adopts a block matching algorithm to estimate motion vectors and uses morphological tools such as open-close by reconstruction and the region-growing version of the watershed algorithm for spatial segmentation to improve the temporal segmentation. In order to determine the reliable motion vectors, this paper also proposes a change detection algorithm and a multi-candidate pro- screening motion estimation method. Preliminary simulation results demonstrate that the proposed scheme is feasible. The main advantage of the scheme is its low computational load.
基金Acknowledgements This work is supported by the National Natural Science Foundation of China （Nos. 21574094 and 21304064）, the Natural Science Foundation of Jiangsu Province （Nos. BK20130292 and BK20150314）, a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions （PAPD）, the Fund for Excellent Creative Research Teams of Jiangsu Higher Education Institutions and the projectsponsored by the Scientific Research Foundation for the returned overseas Chinese scholars, State Education Ministry.
文摘In this study, we report a spindle-like micromotor. This device, which is fabricated using a one-step electrospinning method, consists of biodegradable polycaprolactone and an anionic surfactant. Intriguingly, not only can the resulting micromotor move autonomously on the surface of water for a long period of time （-40 min） due to the Marangoni effect, but it also exhibits a pH sensing behavior due to variations in the surface tension caused by the release of surfactant under different pH conditions. More interestingly, we reveal that the motion-based pH sensing property is size-dependent, with smaller structures exhibiting a higher sensitivity. In addition, since polycaprolactone is a biode- gradable material, the micromotor described in this study can be easily degraded in solution. Hence, features such as one-step fabrication, motion readout, and biodegradability render this micromotor an attractive candidate for sensing algplications.
文摘Sustaining awkward postures and overexertion are common factors in construction industry that result in work-related injuries of workers. To address there safety and health issues, conventional observational methods on the external causes are tedious and subjective, while the direct measurement on the internal causes is intrusive leading to productivity reduction. Therefore, it is essential to construct an effective approach that maps the external and internal causes to realize the non-intrusive identification of safety and health risks. This research proposes a theoretical method to analyze the postures tracked by videos with biomechanical models. Through the biomechanical skeleton representation of human body, the workload and joint torques are rapidly and accurately evaluated based on the rotation angles of joints. The method is then demonstrated by two case studies about(1) plastering and(2) carrying. The experiment results illustrate the changing intramuscular torques across the construction activities in essence, validating the proposed approach to be effective in theory.
文摘为解决视频拼接过程中配准效率低、实时性差的问题,提出基于网格运动统计的视频图像快速拼接算法。将改进的快速旋转不变性特征(Oriented FAST and Rotated BRIEF,ORB)和网格运动统计(Grid-based Motion Statistics,GMS)算法相结合,优化图像金字塔尺度空间结构,引入快速视网膜关键点算法对特征点进行二进制描述,并采用最佳缝合线和拉普拉斯融合算法对多路视频进行拼接。经实验结果分析,提高了视频拼接的鲁棒性和实时性。与传统算法相比,图像配准速度在亮度、旋转、尺度方面分别提高28.7%、35.2%、33.9%,准确率分别提升21.6%、10.6%、9.9%。
