二进小波与扩散滤波结合的光学相干层析图像降噪-吉林大学学报.PDF

第43卷　 增刊 吉林 大 学 学报 ( 工 学版 ) 　 Vol.43　 Sup. 2013年3月 Journal of Jilin University (Engineering and Technology Edition) 　 Mar. 2013 二进小波与扩散滤波结合的光学相干层析图像降噪 1 1 2 张　 田 ,孙延奎 ,田小林 (1.清华大学计算机科学与技术系,北京100084;2.澳门科技大学资讯科技学院,澳门特别行政区) 摘　 要:斑点抑制各向异性扩散(SRAD)是一种重要的图像降噪方法。 将二进小波与SRAD 结合,提出一种光学相干层析图像的二进小波扩散滤波降噪方法。 该方法利用二进小波分解 得到的不同尺度间小波系数的相关性区分边缘和噪声,修改SRAD 中扩散系数得到新的扩散 系数计算公式。 实验表明,新方法具有更好的降噪能力,降噪后得到的图像的信噪比和对比度 噪声比率等量化衡量指标都优于经典SRAD方法。 关键词:光学相干层析;图像降噪;各向异性扩散;二进小波 中图分类号:TN911.73　 　 文献标志码:A　 　 文章编号:1671-5497(2013)Sup.-0340-05 Optical coherence tomography image denoising method by merging dyadic wavelet and anisotropic diffusion filter 1 1 2 ZHANGTian ,SUN Yan-kui ,TIAN Xiao-lin (1.Department of Computer Science and Technology,Tsinghua University,Beijing 100084,China;2. Faculty of Information Technology,Macau University of Science and Technology,Macao SAR,China) Abstract:Speckle reduction anisotropic diffusion (SRAD)is an important method to denoise speckle noise.A new method was presented to denoise optical coherence tomography (OCT) speckle by combining SRAD and dyadic wavelet.Interscale dependency of dyadicwaveletcoefficientswasusedtodistinguishedgesfromnoises. A quantitative estimation was provided to evaluate the probability that a pixel lied in edge-related regions or homogenous regions,and the probability was used to modify the diffusion coefficient in SRAD to get a new anisotropic diffusion method,which exhibited an increased ability to detect and suppress strong noises,while still equally was good at preserving image edges. Experiments show that the denoising performance of our method is better than that of SRAD. Key words:optica