共查询到20条相似文献，搜索用时 234 毫秒
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《科技通报》2016,(3)
目的:利用SVM对新疆高发病哈萨克族食管癌X线医学图像进行分类研究。方法:随机选取正常食管和缩窄型食管癌X线医学图像各120张,运用灰度直方图法和灰度共生矩阵法提取图像的特征,采用Lib-SVM工具箱,在SVM类型设置上选择C-SVC,选择4种核函数,通过调整核函数的参数与C-SVC分类器的参数进行实验。结果:利用灰度直方图法提取的特征量进行分类时,线性核函数和RBF核函数的分类准确率较高,均可达92.5%;利用灰度共生矩阵法提取的特征量进行分类时,线性核函数、RBF核函数、Sigmoid核函数的分类准确率较高,均可达87.5%;利用灰度直方图特征和灰度共生矩阵特征组成的综合特征进行分类时,多项式核函数和RBF核函数的准确率较高,均可达97.5%。结论:灰度直方图特征的分类能力优于灰度共生矩阵特征;综合特征的分类能力优于单一特征的分类能力;RBF核函数的分类性能较其他核函数突出。SVM对食管癌X线医学图像具有较高的分类识别率,为新疆高发病哈萨克族食管癌的计算机辅助诊断系统的研究奠定了基础。 相似文献
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传统的SURF方法对动画图像角度特征匹配准确度较低,计算开销大,稳健性不好。引入Hes.sian矩阵尺度极值检测技术,提出一种改进的基于加速鲁棒特征匹配算法,实现对动画图像的角度特征优化匹配。首先基于摄像机的成像原理利用灰度直方图二进制均衡算法对图像进行增强处理,采用Hessian矩阵检测出图像每个尺度中的极值点,把图像角度极值点聚焦在图像的仿射闭合区域。提取仿射闭合区域的图像角度特征,使用SURF双向匹配算法实现角度特征优化匹配。仿真实验表明,改进方法能使图像的角度特征匹配准确度大幅提升,特征匹配准确率提高显著,有较好的鲁棒性和实时性。 相似文献
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对模糊图像的多尺度分割,是解决许多计算机视觉处理问题的基础。传统的图像分割算法采用基于小波变换的局部特征匹配方法,无法有效去除光照的干扰,对运动目标图像的分割效果不好。提出一种基于模糊图像边缘能量特征提取的运动目标图像的去光照干扰分割方法。计算去光照干扰后的运动目标图像振幅分量和频率分量,采用混合函数控制曲线方法生成运动目标图像时间序列,计算每个尺度下计算运动目标图像的边缘能量特征,进行图像区域特征的非同态块匹配分割,最终生成灰度直方图二进制均衡系数,实现了运动目标图像的准确分割,去除了光照干扰。仿真结果表明,该算法具有分割结果准确,抗干扰能力较好,图像分割质量较优。 相似文献
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本文在基于灰度图像分割的基础上对传统遗传算法进行改进,提出基于染色体、基因位的改进遗传算法.该方法利用图像的直方图,对进行初始种群预处理,减少遗传算法的迭代次数.实验表明,改进的遗传算法应用于灰度图像分割能取得较好的效果. 相似文献
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基于最大信息熵原理的显微细胞图像多阈值分割算法 总被引：1，自引：0，他引：1
王任挥 《内蒙古科技与经济》2010,(18):58-60
文章应用最大信息熵原理,实现了显微细胞图像的多阈值分割。选用图像像素灰度值和各灰度值在图像中出现的概率构成一维灰度直方图,针对显微细胞图像多域值分割的要求,将一维灰度直方图划分成3个独立的子块,确定各个子块的信息熵。根据最大信息熵原理,当总的信息熵为最大值时,确定的阈值t1、t2为最佳分割阈值。 相似文献
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图像增强技术有直方图处理、平滑处理、尖锐化处理等。图像增强技术是为了某种应用目的去改善图像的质量。图像增强技术可以归纳为:以灰度映射变换为基础的空域处理和以数字滤波方法为基础的频域处理。介绍了图像的线性灰度变换技术,利用Java实现了图像的灰度变换。 相似文献
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《Journal of The Franklin Institute》2007,344(3-4):243-256
A new pre-processing method for colour fundus images with adaptive contribution of the red channel is proposed. Based on a condition that is developed in this paper, this method utilises the intensity information from both red and green channels instead of using only the green channel as in the usual practice. The histogram matching is used to modify the histogram of the green channel by using the histogram of the red channel (of the same retinal image) to obtain a new processed image having the advantages of both channels. This method can be used to correct non-uniform illumination in colour fundus images or as a pre-processing step in the automatic analysis of retinal images.Results show that the use of histogram matched (HM) image give better performance than using the green channel image when employing the two-dimensional matched filter to detect retinal blood vessels. At specificity of 90%, in case of abnormal images, sensitivity increased from 76% when using the green channel image to 82% when using the HM image compared with 81% when using the piece-wise threshold probing method. In case of normal images, at the same specificity, the sensitivity obtained when using green channel image or HM image was 87% compared with 88% for the piece-wise threshold probing method. 相似文献
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Content-based image retrieval for medical images is a primary technique for computer-aided diagnosis. While it is a premise for computer-aided diagnosis system to build an efficient medical image database which is paid less attention than that it deserves. In this paper, we provide an efficient approach to develop the archives of large brain CT medical data. Medical images are securely acquired along with relevant diagnosis reports and then cleansed, validated and enhanced. Then some sophisticated image processing algorithms including image normalization and registration are applied to make sure that only corresponding anatomy regions could be compared in image matching. A vector of features is extracted by non-negative tensor factorization and associated with each image, which is essential for the content-based image retrieval. Our experiments prove the efficiency and promising prospect of this database building method for computer-aided diagnosis system. The brain CT image database we built could provide radiologists with a convenient access to retrieve pre-diagnosed, validated and highly relevant examples based on image content and obtain computer-aided diagnosis. 相似文献
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XMage is introduced in this paper as a method for partial similarity searching in image databases. Region-based image retrieval is a method of retrieving partially similar images. It has been proposed as a way to accurately process queries in an image database. In region-based image retrieval, region matching is indispensable for computing the partial similarity between two images because the query processing is based upon regions instead of the entire image. A naive method of region matching is a sequential comparison between regions, which causes severe overhead and deteriorates the performance of query processing. In this paper, a new image contents representation, called Condensed eXtended Histogram (CXHistogram), is presented in conjunction with a well-defined distance function CXSim() on the CX-Histogram. The CXSim() is a new image-to-image similarity measure to compute the partial similarity between two images. It achieves the effect of comparing regions of two images by simply comparing the two images. The CXSim() reduces query space by pruning irrelevant images, and it is used as a filtering function before sequential scanning. Extensive experiments were performed on real image data to evaluate XMage. It provides a significant pruning of irrelevant images with no false dismissals. As a consequence, it achieves up to 5.9-fold speed-up in search over the R*-tree search followed by sequential scanning. 相似文献
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基于不平度的快速图像彩色化方法 总被引：1，自引：0，他引：1
黑白图像的彩色化是图像处理领域一个活跃的、有挑战性的研究课题．在总结了其他 图像彩色化方法的基础上,提出了一种新型的快速彩色化方法．该方法以不平度作为颜色扩展 的约束条件,使用热传导方程来代替颜色混合方法使色块边缘更加平滑,从而大大降低了运算复杂度、提高了彩色化效率．实验表明,该方法不仅速度快,而且能够大大简化对初始着色的要求,并达到很好的彩色化效果． 相似文献
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A novel visually imperceptible image hiding scheme based on VQ compression and LSB modification is introduced in this article. Multiple secret images can be simultaneously and imperceptibly hid into another cover image with the same image size by the proposed scheme. In order to reduce the volume of secret images to be hid, a codebook is first generated from the secret images and these images are encoded into binary indices by the vector quantization technique. Then the compressed data of secret images are embedded into the VQ codebook used in the encoding procedure by an adaptive least-significant-bits (LSB) modification technique. For the security purpose, the slightly modified codebook is further encrypted into a meaningless data stream by the DES cryptosystem. Finally, the encrypted codebook is embedded into the cover image using the greedy LSB modification technique. Simulation results show that the proposed scheme provides a good improvement in the visual quality of the extracted secret images and the cover image at the receiver. In addition, the proposed scheme provides better hiding capacity for the cover image than earlier works. 相似文献