期刊文献+
共找到2篇文章
< 1 >
每页显示 20 50 100
一种低对比度CT图像的血管分割方法 被引量:1
1
作者 叶建平 郭李云 田毅 《计算机系统应用》 2015年第2期184-188,共5页
CT图像血管分割技术在疾病的诊断,手术规划等许多实际应用中发挥着重要的作用.由于个体性差异和成像设备的限制,造影后的血管通常存在对比度低和噪声高的缺陷.针对该数据特点提出了一套分割方法,首先采用直方图对图像进行预处理,以增强... CT图像血管分割技术在疾病的诊断,手术规划等许多实际应用中发挥着重要的作用.由于个体性差异和成像设备的限制,造影后的血管通常存在对比度低和噪声高的缺陷.针对该数据特点提出了一套分割方法,首先采用直方图对图像进行预处理,以增强血管和周围区域的对比度;其次,改进Hessian矩阵血管增强的判别方法,使其对细小和模糊的管状结构更加敏感;最后,采用区域生长算法对增强后的数据进行血管提取,获得血管分支较丰富的分割数据.实验证明本文的分割方法可以准确地实现血管分割,有效地避免了误分割,具有较好的鲁棒性. 展开更多
关键词 血管分割 直方图预处理 Hessian矩阵血管增强 区域生长算法
在线阅读 下载PDF
Fast implementation of kernel simplex volume analysis based on modified Cholesky factorization for endmember extraction 被引量:1
2
作者 Jing LI Xiao-run LI +1 位作者 Li-jiao WANG Liao-ying ZHAO 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2016年第3期250-257,共8页
Endmember extraction is a key step in the hyperspectral image analysis process. The kernel new simplex growing algorithm (KNSGA), recently developed as a nonlinear alternative to the simplex growing algorithm (SGA... Endmember extraction is a key step in the hyperspectral image analysis process. The kernel new simplex growing algorithm (KNSGA), recently developed as a nonlinear alternative to the simplex growing algorithm (SGA), has proven a promising endmember extraction technique. However, KNSGA still suffers from two issues limiting its application. First, its random initialization leads to inconsistency in final results; second, excessive computation is caused by the iterations of a simplex volume calculation. To solve the first issue, the spatial pixel purity index (SPPI) method is used in this study to extract the first endrnember, eliminating the initialization dependence. A novel approach tackles the second issue by initially using a modified Cholesky fac- torization to decompose the volume matrix into triangular matrices, in order to avoid directly computing the determinant tauto- logically in the simplex volume formula. Theoretical analysis and experiments on both simulated and real spectral data demonstrate that the proposed algorithm significantly reduces computational complexity, and runs faster than the original algorithm. 展开更多
关键词 Endmember extraction Modified Cholesky factorization Spatial pixel purity index (SPPI) New simplex growingalgorithm (NSGA) Kernel new simplex growing algorithm (KNSGA)
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部