The theory of detecling ridges in the modulus of the continuous wavelet transform is presented as well as reconstructing signal by using information on ridges,To periodic signal we suppose Morlet wavelet as basic wave...The theory of detecling ridges in the modulus of the continuous wavelet transform is presented as well as reconstructing signal by using information on ridges,To periodic signal we suppose Morlet wavelet as basic wavelet, and research the local extreme point and extrema of the wavelet transform on periodic function for the collection of signal＇ s instantaneous amplitude and period.展开更多
Atmospheric conditions induced by suspended particles, such as fog and haze, severely alter the scene appearance.In this paper, we propose a novel defogging method based on the local extrema, aiming at improving the i...Atmospheric conditions induced by suspended particles, such as fog and haze, severely alter the scene appearance.In this paper, we propose a novel defogging method based on the local extrema, aiming at improving the image visibility under foggy or hazy weather condition. The proposed method utilizes atmospheric scattering model to realize the fog removal.It applies the local extrema method to figure out three pyramid levels to estimate atmospheric veil, and manipulates the tone and contrast of details at different scales through multi-scale tone manipulation algorithm. The results on the experiments of comparison with traditional methods demonstrate that the proposed method can achieve more accurate restoration for the color and details, resulting in a great improvement in image visibility.展开更多
经验模分解(Em p iricalM ode D ecom position,EMD)是希尔伯特-黄变换(HHT)的核心,而经验模分解方法的关键是对提取固有模式函数(Intrinsic m ode function,IM F)时所谓边缘效应问题的处理。提出了极值点对称延拓方法,用来对边缘效应...经验模分解(Em p iricalM ode D ecom position,EMD)是希尔伯特-黄变换(HHT)的核心,而经验模分解方法的关键是对提取固有模式函数(Intrinsic m ode function,IM F)时所谓边缘效应问题的处理。提出了极值点对称延拓方法,用来对边缘效应问题进行处理。算例分析结果表明该方法的算法简单,计算速度快,能有效地抑制EMD分解时的边缘效应,分解得到的固有模式函数完备地体现了原信号真实的频率和幅值信息。在信号重构时不会带来原始信号的畸变。展开更多
基金Supported by the National Natural Science Founda-tion of China (49771060)
文摘The theory of detecling ridges in the modulus of the continuous wavelet transform is presented as well as reconstructing signal by using information on ridges,To periodic signal we suppose Morlet wavelet as basic wavelet, and research the local extreme point and extrema of the wavelet transform on periodic function for the collection of signal＇ s instantaneous amplitude and period.
基金supported by Beijing Municipal Education Commission Science and Technology Development Plan key project(KZ201210005007)the Beijing Municipal Education Commission Science and Technology Development Plan project(KM201010005011,KM201310005020)
文摘Atmospheric conditions induced by suspended particles, such as fog and haze, severely alter the scene appearance.In this paper, we propose a novel defogging method based on the local extrema, aiming at improving the image visibility under foggy or hazy weather condition. The proposed method utilizes atmospheric scattering model to realize the fog removal.It applies the local extrema method to figure out three pyramid levels to estimate atmospheric veil, and manipulates the tone and contrast of details at different scales through multi-scale tone manipulation algorithm. The results on the experiments of comparison with traditional methods demonstrate that the proposed method can achieve more accurate restoration for the color and details, resulting in a great improvement in image visibility.
文摘经验模分解(Em p iricalM ode D ecom position,EMD)是希尔伯特-黄变换(HHT)的核心,而经验模分解方法的关键是对提取固有模式函数(Intrinsic m ode function,IM F)时所谓边缘效应问题的处理。提出了极值点对称延拓方法,用来对边缘效应问题进行处理。算例分析结果表明该方法的算法简单,计算速度快,能有效地抑制EMD分解时的边缘效应,分解得到的固有模式函数完备地体现了原信号真实的频率和幅值信息。在信号重构时不会带来原始信号的畸变。
