Browsing by Author "Wang, S. -J."

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Visible colour difference-based quantitative evaluation of colour segmentation
(2006-10-01)
Chen, H. -C.
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Wang, S. -J.
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
The authors present the use of visible colour difference in a new quantitative evaluation scheme for colour segmentation. To avoid directly evaluating the subjectively perceived quality of colour segmentation, two objective visual quantities, the quantity of missing boundaries and the quantity of fake boundaries, are considered. To explore bow missing boundaries and fake boundaries affect the perceived quality of colour segmentation, a few visual rating experiments are made. On the other hand, to fit for humans' visual perception on colour difference, the visible colour difference is defined. Based on the experiments and the visible colour difference, two measures, named intra-region visual error and inter-region visual error, are designed to estimate the degrees of missing boundaries and fake boundaries, respectively. With these two measures, a complete scheme for the evaluation of colour segmentation is proposed. The simulation results demonstrate that this new scheme may evaluate segmentation results without any ground truth, and could help the automatic selection of parameter settings for a given segmentation algorithm.
White-light emissions from p-type porous silicon layers by high-temperature thermal annealing
(2009-01-01)
Tsai, W. -C.
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Lin, J. -C.
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Huang, K. -M.
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Yang, P. -Y.
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Wang, S. -J.
In this study, the white-light emissions, including red, green and blue colors, appearing on the same porous silicon samples are originally introduced by a thermal-annealing method. The SEM, FTIR, and PL are discussed for different annealing temperature cases. The FTIR is used to monitor the chemical bonding structures of the PS samples under different annealing temperatures. The results show that the variation of chemical bonding relates to the variation of the emission wavelength. The emission intensities of the blue-green-light components are enhanced with the increase of annealing temperature. The PL spectra cover the entire visible region under the excitations of He-Cd laser beam, and a strong white-light emission can be observed by the naked eye at room temperature. Copyright (C) EPLA, 2009