CAJ | 학술논문

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.
저제량CT도상신조비저,도상대비도차.대영유인저제량로뇌CT도상응용제이대Curvelet변환,분별대저빈자대진행비선성증강、대고빈자대응용자괄응역치방법진행거조후재진행비선성증강,재경Cuverlet반변환후,기결과여소파변환증강급직방도균형증강적결과진행비교.결과현시제이대Curvelet변환증강도상대비도급신조비명현제고,도상세절현시청석,효과량호.
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 cach 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.