An approach to detection of moving objects in video sequences, with application to video surveillance is presented. The algorithm combines two kinds of change points, which are detected from the region-based frame dif...An approach to detection of moving objects in video sequences, with application to video surveillance is presented. The algorithm combines two kinds of change points, which are detected from the region-based frame difference and adjusted background subtraction. An adaptive threshold technique is employed to automatically choose the threshold value to segment the moving objects from the still background. And experiment results show that the algorithm is effective and efficient in practical situations. Furthermore, the algorithm is robust to the effects of the changing of lighting condition and can be applied for video surveillance system.展开更多
The effect of external vibration on the velocity uniformity of the moving mechanism of the angular mir⁃ror translational Fourier transform interferometer(hereinafter referred to as interferometer)can be quantitatively...The effect of external vibration on the velocity uniformity of the moving mechanism of the angular mir⁃ror translational Fourier transform interferometer(hereinafter referred to as interferometer)can be quantitatively analysed by the interferometer optical range difference velocity stability.The article proposes a more comprehen⁃sive method of analysing the optical range difference velocity uniformity for the reliability of the interferometer ki⁃nematic mechanism under the influence of on-orbit microvibration in the process of space spectroscopy detection.The method incorporates the structural response of the interferometer caused by external excitation into the stabili⁃ty analysis as one of the influencing factors,so as to reflect the reliability of the interferometer in orbit more realis⁃tically,and judge the microvibration criticality that the interferometer can withstand more accurately.At the same time,an optical surface model of the interferometer is established to further theoretically characterise the effect of microvibration on the homogeneity of the interferometric mechanism.The method discussed in the article pro⁃vides a way of thinking for the judgement of the reliability of the mechanism movement under the external excita⁃tion perturbation as well as the research on the optimisation of the mechanism control.展开更多
文摘An approach to detection of moving objects in video sequences, with application to video surveillance is presented. The algorithm combines two kinds of change points, which are detected from the region-based frame difference and adjusted background subtraction. An adaptive threshold technique is employed to automatically choose the threshold value to segment the moving objects from the still background. And experiment results show that the algorithm is effective and efficient in practical situations. Furthermore, the algorithm is robust to the effects of the changing of lighting condition and can be applied for video surveillance system.
文摘The effect of external vibration on the velocity uniformity of the moving mechanism of the angular mir⁃ror translational Fourier transform interferometer(hereinafter referred to as interferometer)can be quantitatively analysed by the interferometer optical range difference velocity stability.The article proposes a more comprehen⁃sive method of analysing the optical range difference velocity uniformity for the reliability of the interferometer ki⁃nematic mechanism under the influence of on-orbit microvibration in the process of space spectroscopy detection.The method incorporates the structural response of the interferometer caused by external excitation into the stabili⁃ty analysis as one of the influencing factors,so as to reflect the reliability of the interferometer in orbit more realis⁃tically,and judge the microvibration criticality that the interferometer can withstand more accurately.At the same time,an optical surface model of the interferometer is established to further theoretically characterise the effect of microvibration on the homogeneity of the interferometric mechanism.The method discussed in the article pro⁃vides a way of thinking for the judgement of the reliability of the mechanism movement under the external excita⁃tion perturbation as well as the research on the optimisation of the mechanism control.
