A novel diversity-sampling based nonparametric multi-modal background model is proposed. Using the samples having more popular and various intensity values in the training sequence, a nonparametric model is built for ...A novel diversity-sampling based nonparametric multi-modal background model is proposed. Using the samples having more popular and various intensity values in the training sequence, a nonparametric model is built for background subtraction. According to the related intensifies, different weights are given to the distinct samples in kernel density estimation. This avoids repeated computation using all samples, and makes computation more efficient in the evaluation phase. Experimental results show the validity of the diversity- sampling scheme and robustness of the proposed model in moving objects segmentation. The proposed algorithm can be used in outdoor surveillance systems.展开更多
With the recent development of diversity electro-optic sampling(DEOS),significant progress has been made in the range of applicability of single-shot EOS measurements,allowing broadband THz waveforms to be captured in...With the recent development of diversity electro-optic sampling(DEOS),significant progress has been made in the range of applicability of single-shot EOS measurements,allowing broadband THz waveforms to be captured in a single shot over large temporal windows.In addition to the decrease in acquisition time compared to standard multishot data acquisition,this technique allows measurements on systems far from equilibrium with large shotto-shot noise or with irreversible or poorly repeatable dynamics.Although DEOS has been demonstrated and verified for linearly polarized THz waveforms,we investigate the effects resulting from the presence of a secondary polarization component.This imposes new challenges for accurate waveform reconstruction,and opens the opportunity to measure out complex polarization states such as arbitrary elliptically polarized THz field.We demonstrate a single-shot diversity-electro-optic-sampling-based approach to capture both x-and y-THz fields simultaneously with a single(110)-cut EO crystal for THz polarimetry and ellipsometry over a wide range of frequencies.展开更多
基金Project supported by National Basic Research Program of Chinaon Urban Traffic Monitoring and Management System(Grant No .TG1998030408)
文摘A novel diversity-sampling based nonparametric multi-modal background model is proposed. Using the samples having more popular and various intensity values in the training sequence, a nonparametric model is built for background subtraction. According to the related intensifies, different weights are given to the distinct samples in kernel density estimation. This avoids repeated computation using all samples, and makes computation more efficient in the evaluation phase. Experimental results show the validity of the diversity- sampling scheme and robustness of the proposed model in moving objects segmentation. The proposed algorithm can be used in outdoor surveillance systems.
文摘With the recent development of diversity electro-optic sampling(DEOS),significant progress has been made in the range of applicability of single-shot EOS measurements,allowing broadband THz waveforms to be captured in a single shot over large temporal windows.In addition to the decrease in acquisition time compared to standard multishot data acquisition,this technique allows measurements on systems far from equilibrium with large shotto-shot noise or with irreversible or poorly repeatable dynamics.Although DEOS has been demonstrated and verified for linearly polarized THz waveforms,we investigate the effects resulting from the presence of a secondary polarization component.This imposes new challenges for accurate waveform reconstruction,and opens the opportunity to measure out complex polarization states such as arbitrary elliptically polarized THz field.We demonstrate a single-shot diversity-electro-optic-sampling-based approach to capture both x-and y-THz fields simultaneously with a single(110)-cut EO crystal for THz polarimetry and ellipsometry over a wide range of frequencies.
