第二代Curvelet变换在低剂量CT图像增强中的应用  

Low dose CT image enhancement based on second generation Curvelet transform

作　　者：张涛[1] 王宾[1] 杨立娟[2] 齐乃新[3] 

机构地区：[1]西北大学信息学院,西安710069 [2]西安市第四医院CT室,西安710004 [3]西安交通大学医学院第二附属医院CT室,西安710004

出　　处：《计算机工程与应用》2010年第6期191-193,共3页Computer Engineering and Applications

基　　金：陕西省科技计划(No.2006k09-G1(2));西安市科技计划(No.YF07138)

摘　　要：低剂量CT图像信噪比低,图像对比度差。对婴幼儿低剂量颅脑CT图像应用第二代Curvelet变换,分别对低频子带进行非线性增强、对高频子带应用自适应域值方法进行去噪后再进行非线性增强,再经Cuverlet反变换后,其结果与小波变换增强及直方图均衡增强的结果进行比较。结果显示第二代Curvelet变换增强图像对比度及信噪比明显提高,图像细节显示清晰,效果良好。Low dose CT has low Signal-Noise Ratio（SNR） and bad contrast.The second generation Curvelet transform is used to enhanced low dose CT images of infant brain.Firstly,the CT source images are decomposed by Curvelet transform.Then nonlinear enhancing function is applied to enhance the image＇s global contrast in the low frequency sub-band,and threshold denoising method is combined with non-linear gain method,it can reduce the noise and enhance the details of image at each scale in the high frequency sub-band.Compared with wavelet and histogram equalization,enhanced images based on the second generation Curvelet transform show that image SNR and contrast are increased,image edges are preserved.It has a good visual effect.

关 键 词：CURVELET变换 图像增强 低剂量CT 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]