首先论述新型图信号处理(Graph Signal Processing,GSP)技术的基本概念和相关研究进展,其中包括图拓扑结构、图傅里叶变换、滤波及图学习。鉴于语音信号是一种非平稳和非线性的信号,为此,文中研究基于GSP技术的语音信号的图映射理论,即...首先论述新型图信号处理(Graph Signal Processing,GSP)技术的基本概念和相关研究进展,其中包括图拓扑结构、图傅里叶变换、滤波及图学习。鉴于语音信号是一种非平稳和非线性的信号,为此,文中研究基于GSP技术的语音信号的图映射理论,即将时域语音信号映射为图域的语音图信号,通过设计语音图信号的图拓扑结构和图邻接矩阵来研究语音图信号的内在潜藏关系,进而设计优于经典DSP的语音图信号消噪算法和系统。在此研究基础上,进一步讨论相关实际应用问题,例如麦克风阵列环境下如何通过GSP技术处理麦克风阵列声源(说话人)的定位及追踪问题。期望基于GSP技术语音图信号处理理论,为语音识别、合成、编码、增强等各个领域的图信号处理奠定理论基础。展开更多
A new chaotic image encryption scheme based on permutation and substitution in the Fourier domain is presented.Fractional Fourier Transform(FRFT)is used before the encryption scheme to get a large degree of randomizat...A new chaotic image encryption scheme based on permutation and substitution in the Fourier domain is presented.Fractional Fourier Transform(FRFT)is used before the encryption scheme to get a large degree of randomization.The permutation is achieved by Baker map and the substitution by a key-related-to-plain-image algorithm based on the modified Logistic map.Modification of the Logistic map is developed to increase the space of the encryption key,and hence increase the security.The key of the encryption algorithm dependents on the plain image,and thus,the cipher image is sensitive to both the initial key and the plain image to resist known-plaintext and chosen plaintext attacks.The key space is large and hence the algorithm can effectively resist brute-force attacks.The proposed scheme is examined using different performance evaluation metrics and the results prove that the proposed scheme is highly secure,and it can effectively resist different attacks.展开更多
文摘首先论述新型图信号处理(Graph Signal Processing,GSP)技术的基本概念和相关研究进展,其中包括图拓扑结构、图傅里叶变换、滤波及图学习。鉴于语音信号是一种非平稳和非线性的信号,为此,文中研究基于GSP技术的语音信号的图映射理论,即将时域语音信号映射为图域的语音图信号,通过设计语音图信号的图拓扑结构和图邻接矩阵来研究语音图信号的内在潜藏关系,进而设计优于经典DSP的语音图信号消噪算法和系统。在此研究基础上,进一步讨论相关实际应用问题,例如麦克风阵列环境下如何通过GSP技术处理麦克风阵列声源(说话人)的定位及追踪问题。期望基于GSP技术语音图信号处理理论,为语音识别、合成、编码、增强等各个领域的图信号处理奠定理论基础。
文摘A new chaotic image encryption scheme based on permutation and substitution in the Fourier domain is presented.Fractional Fourier Transform(FRFT)is used before the encryption scheme to get a large degree of randomization.The permutation is achieved by Baker map and the substitution by a key-related-to-plain-image algorithm based on the modified Logistic map.Modification of the Logistic map is developed to increase the space of the encryption key,and hence increase the security.The key of the encryption algorithm dependents on the plain image,and thus,the cipher image is sensitive to both the initial key and the plain image to resist known-plaintext and chosen plaintext attacks.The key space is large and hence the algorithm can effectively resist brute-force attacks.The proposed scheme is examined using different performance evaluation metrics and the results prove that the proposed scheme is highly secure,and it can effectively resist different attacks.
