基于非线性复扩散耦合冲激滤波器的图像放大算法研究

为了提高放大算法的适应性,采用改进的非线性复扩散和自适应冲激滤波器,提出了一种图像放大方法。根据像素局部方差进行自适应改变扩散门限,扩散图像的虚部除以扩散时间以消除扩散时间的影响,特别是初期扩散近似线性扩散的特性,得到改进的复扩散模型耦合冲激滤波器进行无噪图像放大。对于噪声图像放大,根据像素局部方差进行自适应非线性复扩散,耦合局部方差约束的冲激滤波器增强模糊的图像边缘和细节。自适应非线性复扩散通过局部方差和图像二阶导数相结合分辨边缘和噪声,对噪声进行平滑的同时保持边缘,克服了复扩散不能分辨噪声和边缘的缺陷,同时保持复扩散保护斜坡结构,免除阶梯效应的优点。仿真实验验证了所提算法不仅对无噪图像有较好的放大效果,而且对一定范围的噪声图像也有较好的放大效果。

FREQUENCY-DOMAIN IMPLEMENTATION OF FILTERED-X ALGORITHMS WITH ON-LINE SYSTEM IDENTIFICATION FOR VIBRATION CONTROL

This paper describes the implementation of frequency-domain least mean squares (LMS) and Filtered-X algorithms and compares the performance of the frequencydomain adaptive control algorithm to a comparable timedomain controller. When the frequency-domain LMS step size is allowed to vary as a function of frequency,the frequency-domain algorithm exhibits a better vibration reduction than the time-domain algorithm for the weaker frequencies in the energy spectrum.