期刊文献+
共找到2篇文章
< 1 >
每页显示 20 50 100
自适应非局部均值滤波与小波相结合的脑部CT去噪研究 被引量:1
1
作者 张爱桃 陈小茜 +3 位作者 肖雨 郭东敏 周旭 李连捷 《中国医疗设备》 2021年第12期73-77,共5页
目的利用非局部均值滤波与小波相结合的算法,抑制脑部CT图像噪声,提高图像的质量。方法通过仿真实验确定不同噪声水平下的滤波系数,然后采用真实的含噪脑CT图像进行验证,并与传统非局部均值滤波进行比较。最后采用配对t检验,对该方法滤... 目的利用非局部均值滤波与小波相结合的算法,抑制脑部CT图像噪声,提高图像的质量。方法通过仿真实验确定不同噪声水平下的滤波系数,然后采用真实的含噪脑CT图像进行验证,并与传统非局部均值滤波进行比较。最后采用配对t检验,对该方法滤波前后的图像峰值信噪比进行统计学分析。结果该方法能够使含有白噪声的CT图像的峰值信噪比提高5~10 dB,高出传统非局部均值滤波后图像3~5 dB。滤波前后的图像峰值信噪比具有统计学差异(P<0.001)。结论结合小波的自适应非局部均值滤波可以对不同噪声水平的脑CT图像进行自适应处理,有效去除噪声,提高峰值信噪比,同时保留图像的细节及边缘,改善图像质量。 展开更多
关键词 脑CT图像 图像去噪 自适应非局部均值滤 小波噪声方差估计
下载PDF
Denoising of hyperspectral imagery by cubic smoothing spline in the wavelet domain 被引量:1
2
作者 陈绍林 Hu Xiyuan +1 位作者 Peng Silong Zhou Zhiqiang 《High Technology Letters》 EI CAS 2014年第1期54-62,共9页
The acquired hyperspectral images (HSIs) are inherently attected by noise wlm Dano-varylng level, which cannot be removed easily by current approaches. In this study, a new denoising method is proposed for removing ... The acquired hyperspectral images (HSIs) are inherently attected by noise wlm Dano-varylng level, which cannot be removed easily by current approaches. In this study, a new denoising method is proposed for removing such kind of noise by smoothing spectral signals in the transformed multi- scale domain. Specifically, the proposed method includes three procedures: 1 ) applying a discrete wavelet transform (DWT) to each band; 2) performing cubic spline smoothing on each noisy coeffi- cient vector along the spectral axis; 3 ) reconstructing each band by an inverse DWT. In order to adapt to the band-varying noise statistics of HSIs, the noise covariance is estimated to control the smoothing degree at different spectra| positions. Generalized cross validation (GCV) is employed to choose the smoothing parameter during the optimization. The experimental results on simulated and real HSIs demonstrate that the proposed method can be well adapted to band-varying noise statistics of noisy HSIs and also can well preserve the spectral and spatial features. 展开更多
关键词 DENOISING hyperspectral imagery cubic spline smoothing wavelet transform spectral smoothness
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部