共查询到18条相似文献,搜索用时 203 毫秒
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目的:不同的医学影像为医生提供不同的医学信息,图像融合技术逐渐成为临床诊断和医学研究的重要手段.方法:本文采用了一种基于不可分离小波框架的图像融合算法.算法首先对已配准的医学图像进行非分离小波分解,把图像分解成低频和高频子图像,针对高频分量和低频分量不同的特点,采用不同的融合规则对其进行融合,最后进行小波逆变换,得到最... 相似文献
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目的: 改善传统医学图象融合方法对细节信息的丢失.方法: 利用contourlet的多尺度、方向性和各向异性等优点,提出了一种基于局域特性匹配度融合的改进算法.首先对原图进行contourlet分解,对分解各子带构造局域特征的匹配度,设定匹配度的阈值,对匹配度在不同阈值范围内的系数进行不同的加权融合;最后对融合系数进行contourlet逆变换得到融合图像.在阈值的选取上,引入混沌遗传算法求解阈值的全局最优解.结果: 运用传统小波变换和本文提出对方法对两组医学图象进行融合处理,客观评价参数表明本文提出的算法效果更优.结论: 该算法能够在保有原图信息的同时,有效的增强细节信息. 相似文献
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目的 通过对医学影像设备图像融合技术的分析,对比研究小波图像融合法的优势.方法 对图像融合各环节进行分析,得到传统融合技术图像和四种小波图像融合后的图像,通过与传统图像融合技术对比,分析各自的成像特点.结果 小波变换的四种融合算法各有优缺点.结论 小波变换融合算法较传统的融合算法效果好. 相似文献
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针对离散小波变换具有平移变化性和弱方向性的特性,本文提出了一种基于双树复小波变换(DT-CWT)统计模型的医学图像纹理检索方法 .该方法 首先利用双树复小波变换系数的平移不变和多方向选择特性,建立广义高斯分布的统计模型,然后基于该模型提取图像的特征矢量,最后利用改进的Log-likelih60d(ILL)相似性测度算法进行纹理图像检索.实验结果 表明,该方法 的检索查准率达到了82.8%,相比于传统的Gabor算法和小波算法都有了较大的提高,对今后的纹理图像检索具有重要的理论与实际意义. 相似文献
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为了提高医学图像融合的可靠性,本文在原小波理论的基础上提出了基于多小波变换的融合方法。此方法能够有效地保留原始图像的重要特征,有着较好的融合效果。 相似文献
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为了提高医学图像融合的可靠性,本文在原小波理论的基础上提出了基于多小波变换的融合方法。此方法能够有效地保留原始图像的重要特征,有着较好的融合效果。 相似文献
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Belén Cruz Zapata Antonio Hernández Niñirola Ali Idri José Luis Fernández-Alemán Ambrosio Toval 《Journal of medical systems》2014,38(8):1-16
Recently image fusion has prominent role in medical image processing and is useful to diagnose and treat many diseases. Digital subtraction angiography is one of the most applicable imaging to diagnose brain vascular diseases and radiosurgery of brain. This paper proposes an automatic fuzzy-based multi-temporal fusion algorithm for 2-D digital subtraction angiography images. In this algorithm, for blood vessel map extraction, the valuable frames of brain angiography video are automatically determined to form the digital subtraction angiography images based on a novel definition of vessel dispersion generated by injected contrast material. Our proposed fusion scheme contains different fusion methods for high and low frequency contents based on the coefficient characteristic of wrapping second generation of curvelet transform and a novel content selection strategy. Our proposed content selection strategy is defined based on sample correlation of the curvelet transform coefficients. In our proposed fuzzy-based fusion scheme, the selection of curvelet coefficients are optimized by applying weighted averaging and maximum selection rules for the high frequency coefficients. For low frequency coefficients, the maximum selection rule based on local energy criterion is applied to better visual perception. Our proposed fusion algorithm is evaluated on a perfect brain angiography image dataset consisting of one hundred 2-D internal carotid rotational angiography videos. The obtained results demonstrate the effectiveness and efficiency of our proposed fusion algorithm in comparison with common and basic fusion algorithms. 相似文献
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提出一种基于小波包分解的多尺度图象边缘检测算法,对经小波包分解所得到的高频部分加以考虑,避免了普通的利用小波分解进行边缘检测时忽略图象高频部分的缺陷.在此基础上,通过对实际图象运用此算法,对其检测效果同其他方法进行分析与比较,结果证明此方法在复杂图象边缘检测中具有较好的效果. 相似文献
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目的 为消除视盘在硬渗出物(EX)分割过程中带来的影响提出了基于区域分类引导的小波Y-Net网络的EX分割算法。方法 该网络为端到端的眼底图像EX分割网络,通过区域分类引导EX分割联合实现了视盘区域检测和EX分割,有效地降低了视盘对EX分割的干扰。为了避免因下采样操作产生信息损失而导致微小EX区域分割失效的问题,该网络进一步引入了离散小波变换(DWT)和离散小波逆变换(IDWT)取代传统的池化下采样和上采样操作。同时,采用了基于残差连接的Inception模块获取多尺度特征。所提出的算法在IDRiD、e-ophtha EX数据库上进行训练和测试,并进行像素级评估。结果 区域分类引导的小波Y-Net网络在IDRiD、e-ophtha EX数据库上分别获得0.9858、0.9938的准确率以及0.9880、0.9986的受试者工作特征曲线下面积(AUC)。结论 本文提出的方法能够有效地规避视盘的影响,保留图像细节信息,提升EX的分割效果。 相似文献
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目的 研究一种基于外部定位框的PET和CT图像异机融合新方法,实现PET和CT异机图像的准确融合.方法 采用自行研制的新型外部定位框,获取C仰ET异机扫描定位图像,利用固定的标记点进行配准,最后运用变分法和小波变换结合进行图像融合.结果 以CT图像为基准用灰度色阶显示,PET图像叠加在CT图像上,用彩色色阶显示,得到基于外部定位架的CT/PET融合后图像.结论 利用该方法获取CT/PET异机扫描定位标记点图像清晰,配准融合后图像准确.该方法具有结构简单和使用方便的特点,值得临床推广. 相似文献
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A new algorithm for medical image retrieval is presented in the paper. An 8-bit grayscale image is divided into eight binary bit-planes, and then binary wavelet transform (BWT) which is similar to the lifting scheme in real wavelet transform (RWT) is performed on each bitplane to extract the multi-resolution binary images. The local binary pattern (LBP) features are extracted from the resultant BWT sub-bands. Three experiments have been carried out for proving the effectiveness of the proposed algorithm. Out of which two are meant for medical image retrieval and one for face retrieval. It is further mentioned that the database considered for three experiments are OASIS magnetic resonance imaging (MRI) database, NEMA computer tomography (CT) database and PolyU-NIRFD face database. The results after investigation shows a significant improvement in terms of their evaluation measures as compared to LBP and LBP with Gabor transform. 相似文献
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Asiya M. Al-Busaidi Lazhar Khriji Farid Touati Mohd Fadlee Rasid Adel Ben Mnaouer 《Journal of medical systems》2017,41(10):166
One of the major issues in time-critical medical applications using wireless technology is the size of the payload packet, which is generally designed to be very small to improve the transmission process. Using small packets to transmit continuous ECG data is still costly. Thus, data compression is commonly used to reduce the huge amount of ECG data transmitted through telecardiology devices. In this paper, a new ECG compression scheme is introduced to ensure that the compressed ECG segments fit into the available limited payload packets, while maintaining a fixed CR to preserve the diagnostic information. The scheme automatically divides the ECG block into segments, while maintaining other compression parameters fixed. This scheme adopts discrete wavelet transform (DWT) method to decompose the ECG data, bit-field preserving (BFP) method to preserve the quality of the DWT coefficients, and a modified running-length encoding (RLE) scheme to encode the coefficients. The proposed dynamic compression scheme showed promising results with a percentage packet reduction (PR) of about 85.39% at low percentage root-mean square difference (PRD) values, less than 1%. ECG records from MIT-BIH Arrhythmia Database were used to test the proposed method. The simulation results showed promising performance that satisfies the needs of portable telecardiology systems, like the limited payload size and low power consumption. 相似文献