In order to reduce noise effectively in the welding defect image and preserve the minutiae information, a noise reduction method of welding defect image based on nonsubsampled contourlet transform(NSCT) and anisotropi...In order to reduce noise effectively in the welding defect image and preserve the minutiae information, a noise reduction method of welding defect image based on nonsubsampled contourlet transform(NSCT) and anisotropic diffusion is proposed. Firstly, an X-ray welding defect image is decomposed by NSCT. Then total variation(TV) model and Catte_PM model are used for the obtained low-pass component and band-pass components, respectively. Finally, the denoised image is synthesized by inverse NSCT. Experimental results show that, compared with the hybrid method of wavelet threshold shrinkage with TV diffusion, the method combining NSCT with P_Laplace diffusion, and the method combining contourlet with TV model and adaptive contrast diffusion, the proposed method has a great improvement in the aspects of subjective visual effect, peak signal-to-noise ratio(PSNR) and mean-square error(MSE). Noise is suppressed more effectively and the minutiae information is preserved better in the image.展开更多
随着医学影像技术快速发展,X线CT已成为二级及以上各医院临床诊断普及方法。然而,国外文献数据表明,X线CT引发的辐射占医源性辐射总数将近50%,易导致癌症、白血病、新陈代谢异常等疾病。由此低剂量X线CT扫描技术相应产生,目前采用降低...随着医学影像技术快速发展,X线CT已成为二级及以上各医院临床诊断普及方法。然而,国外文献数据表明,X线CT引发的辐射占医源性辐射总数将近50%,易导致癌症、白血病、新陈代谢异常等疾病。由此低剂量X线CT扫描技术相应产生,目前采用降低管电流实现扫描剂量减少。Filtered Back of Projection算法重建中由于投影域噪声污染出现条形伪影、噪声。本文提出一种基于全变差先验的低剂量X线CT投影域降噪算法。该算法采用全变差先验融入X线CT投影域实现降噪和保持边缘,仿真数据表明该算法能够有效降低噪声、保持边缘,图像明显优于滤波反投影算法的图像。展开更多
基金Supported by the National Natural Science Foundation of China(No.60872065)Open Foundation of State Key Laboratory of Advanced Welding and Connection,Harbin Institute of Technology(AWPT-M04)Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘In order to reduce noise effectively in the welding defect image and preserve the minutiae information, a noise reduction method of welding defect image based on nonsubsampled contourlet transform(NSCT) and anisotropic diffusion is proposed. Firstly, an X-ray welding defect image is decomposed by NSCT. Then total variation(TV) model and Catte_PM model are used for the obtained low-pass component and band-pass components, respectively. Finally, the denoised image is synthesized by inverse NSCT. Experimental results show that, compared with the hybrid method of wavelet threshold shrinkage with TV diffusion, the method combining NSCT with P_Laplace diffusion, and the method combining contourlet with TV model and adaptive contrast diffusion, the proposed method has a great improvement in the aspects of subjective visual effect, peak signal-to-noise ratio(PSNR) and mean-square error(MSE). Noise is suppressed more effectively and the minutiae information is preserved better in the image.
文摘随着医学影像技术快速发展,X线CT已成为二级及以上各医院临床诊断普及方法。然而,国外文献数据表明,X线CT引发的辐射占医源性辐射总数将近50%,易导致癌症、白血病、新陈代谢异常等疾病。由此低剂量X线CT扫描技术相应产生,目前采用降低管电流实现扫描剂量减少。Filtered Back of Projection算法重建中由于投影域噪声污染出现条形伪影、噪声。本文提出一种基于全变差先验的低剂量X线CT投影域降噪算法。该算法采用全变差先验融入X线CT投影域实现降噪和保持边缘,仿真数据表明该算法能够有效降低噪声、保持边缘,图像明显优于滤波反投影算法的图像。
