Multispectral image fusion method based on intensity-hue-saturation and nonsubsampled three-channels non-separable wavelets

<正>A new multispectral image fusion method based on intensity-hue-saturation(IHS) transform and threechannel non-separable wavelets whose dilation matrix is[2,1;1,1]is proposed.The multi-resolution decompositions of the intensity of multispectral image and panchromatic image are performed in nonsubsampled mode using the three-channel non-separable wavelet filter bank.The approximation images and the detail images of the multi-resolution pyramids are fused.The experimental results show that this method has good visual effect.The performance outperforms the IHS fusion method.the discrete wavelet transform (DWT) fusion method,and the IHS-DWT fusion method in preserving spectral quality and high spatial resolution information.     

面向SDN的安全威胁及其对抗技术研究

软件定义网络(software-defined networks,SDN)通过逻辑集中的网络控制,提高了网络编程的灵活性,但由此引入的安全威胁若被攻击者利用将会直接危及整个网络架构。针对SDN的特性,将安全威胁分类汇总为入侵攻击、异常攻击、DDoS和DoS攻击、欺骗攻击4类。鉴于DDoS和DoS攻击在SDN环境下比在传统网络环境下更具针对性且危害性更大,因此着重从攻击原理、手段和效果方面进行系统论述。最后根据攻击类型对现有对抗方案进行了介绍,并根据现有技术的不足提出未来的研究方向与发展趋势。