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1.
关键帧提取技术是基于内容检索和视频分析的基础。关键帧的使用减少了视频索引的数据量,同时也为视频摘要和检索提供了一个组织框架。首先介绍了目前关键帧提取技术,然后提出了一种基于互信息量的关键帧提取方法,该算法以帧间互信息量来衡量两帧图像内容的相似性,可以对具体镜头按其特点自动提取出一个或多个关键帧。实验结果表明这种方法可以较好地概括视频内容。 相似文献
2.
Medical image registration is the process of finding ageometric transformation between two image-based coordi-nate systems that have the same patient-based coordinates ,i .e .the same anatomic locations .The registered multi-mo-dality images lead to impro… 相似文献
3.
This paper presents a threshold-free maximum a posteriori （MAP） super resolution （SR） algorithm to reconstruct high resolution （HR） images with sharp edges. The joint distribution of directional edge images is modeled as a multidimensional Lorentzian （MDL） function and regarded as a new image prior. This model makes full use of gradient information to restrict the solution space and yields an edge-preserving SR algorithm. The Lorentzian parameters in the cost function are replaced with a tunable variable, and graduated nonconvexity （GNC） optimization is used to guarantee that the proposed multidimensional Lor- entzian SR （MDLSR） algorithm converges to the global minimum. Simulation results show the effectiveness of the MDLSR algorithm as well as its superiority over conventional SR methods. 相似文献
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Mutual information (MI)-based image registration is effective in registering medical images, but it is computationally expensive.
This paper accelerates MI-based image registration by dividing computation of mutual information into spatial transformation
and histogram-based calculation, and performing 3D spatial transformation and trilinear interpolation on graphic processing
unit (GPU). The 3D floating image is downloaded to GPU as flat 3D texture, and then fetched and interpolated for each new
voxel location in fragment shader. The transformed results are rendered to textures by using frame buffer object (FBO) extension,
and then read to the main memory used for the remaining computation on CPU. Experimental results show that GPU-accelerated
method can achieve speedup about an order of magnitude with better registration result compared with the software implementation
on a single-core CPU. 相似文献
6.
盛仲飙 《渭南师范学院学报》2014,(3):43-46
基于互信息的图像检索方法是根据图像的可视性及相似性测度对图像进行检索的方法．首先利用互信息生成一种在统计上有代表性的视觉模式,使用这种模式的分布作为图像内容的描述符;接着利用该内容的描述,设计其互信息的计算方法以衡量图像的相似性．实验结果表明,在图像检索中,相对于其他如KL散度和也规范等方法,互信息是一种更为有效的衡量相似性的方法． 相似文献
7.
针对雾霾天气下有雾图像能见度水平低、在低光照条件下无法有效获得图像细节信息等问题,提出一种基于暗通道先验的Retinex去雾算法。首先采用改进的暗通道先验算法对有雾图像进行初步处理,得到初步复原图像;其次,在得到的去雾图像上进行Retinex图像增强,利用引导滤波对照度分量进行平滑处理,求出反射分量;之后利用S型曲线对反射分量进行增强,以增强图像细节信息,并采用全局自适应与改进的Gamma函数对对比度及亮度进行拉伸调整;最后,运用颜色恢复函数还原色彩。实验结果表明,该算法在平均亮度和对比度方面都得到一定程度的提高,分别至少提高了1.79%和1.07%,平均梯度和信息熵分别至少提高了4.80%和4.79%。 相似文献
8.
刘晨 《喀什师范学院学报》2014,(6):45-49
为了降低图像噪声对分水岭算法产生的过分割的影响,在分水岭算法之前进行滤波预处理.而滤波算法在平滑噪声的同时会丢失图像的边缘结构信息,为了保持在滤波预处理过程中图像的边缘结构信息,使用相似性度量的滤波函数,并且相似性度量从基于像素点的方法扩展到基于图像块的方法. 相似文献
9.
The constrained Viterbi algorithm (C-VA) makes use of some prior reliable information to reduce complexity andimprove performance of Viterbi algorithm (VA). However it can only be used in the concatenate code scheme because thedetection result of cyclic redundancy check code (CRC) is exploited to provide reliable information. In this paper, a differentway is proposed to provide reliable information for C-VA, which is possible to be used in simple codec. Known bits were addedto the set partitioning in hierarchical trees (SPIHT) coded image sequence periodically and directly. They were thought to bereliable information for C-VA in the decoder. Experimental results show that the proposed scheme can obtain much bettererror resilient ability compared with conventional VA under the extremely inferior channel condition if the best desired qualityof reconstructed images can be sacrificed. 相似文献
10.
新完善的WAPI协议安全性分析 总被引：2，自引：0，他引：2
在深入研究中国无线局域网安全标准WAPI接入鉴别过程的基础上,利用CK模型并结合BAN逻辑,对其认证和密钥协商过程安全性进行了形式化分析,证明其能够实现所声称的各种认证及密钥协商目标.进一步的分析结果表明,WAPI不仅具有所声称的各种安全属性,同时还能够有效地实现实体间相互认证、密钥的相互控制、密钥确认、消息完整性校验等安全属性.如果协议中所采用的椭圆曲线加密算法和杂凑算法足够安全,则该协议能够实现STA和AP之间的相互身份认证,可以用于替代原来的无线局域网国际标准中的安全机制,以增强无线局域网的安全性. 相似文献
11.
A novel single-channel blind separation algorithm for permuted motion blurred images is proposed by using blind restoration
in this paper. Both the motion direction and the length of the point spread function (PSF) are estimated by Radon transformation
and extrema a detection. Using the estimated blur parameters, the permuted image is restored by performing the L-R blind restoration
method. The permutation mixing matrices can be accurately estimated by classifying the ringing effect in the restored image,
thereby the source images can be separated. Simulation results show a better separation efficiency for the permuted motion
blurred image with various permutation operations. The proposed algorithm indicates a better performance on the robustness
against Gaussian noise and lossy JPEG compression. 相似文献
12.
分析了基于互信息的多模态图像配准的理论和方法,从信息论的角度分析了互信息的性质以及两幅图像互信息的计算等,同时给出基于互信息的图像配准的基本步骤。 相似文献
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针对传统五线谱识别方法存在谱线过删和漏删的缺点,以及现有音符特征提取方法与谱线删除相互制约的问题,提出一种改进的、无需删除谱线的特征提取方法。在图像预处理阶段保留谱线,将音符与谱线同时投影,结合音符符杆垂直像素数据与音符其它部位像素数据携带的映射特征,对横纵向投影数据进行数理统计分析,得到供音符类型识别的归一化特征值,再利用基准谱线与音符符头的相对位置获取音调信息。实验结果表明,该方法在保证较高识别精度的基础上,进一步提高了识别速率,可以有效识别音符组合形式较复杂的乐谱,对于五线谱识别应用具有重要意义。 相似文献
15.
刘卫平 《徐州师范大学学报(哲学社会科学版)》2007,33(5):35-40
创新的形象思维是创新思维的重要形态。形象思维创新的机制可分为两类,即人脑生理活动机制与其思维信息运动机制。前者存在于人的左右脑功能贯通互补机制与脑生理第二信号反射系统机制这两个方面;后者则存在于思维信息相似性的同构机制与思维信息的整合机制,即各种思维信息按照事物内在的本质逻辑而加以贯通融合,以形成思维整体结构过程的必然性。形象思维创新的运动机制必然形成以下自身活动的内在规律:1.意象互渗同构律,即"意"与"象"相互渗透、融为一体,建构为具有创新意义的形象思维成果;2.形象共殊结合律,即借助于思维想象力的发挥,共象材料与殊象材料相互渗透、相互结合;3.思维时空结合律,即各种形象材料在特定思维时空意义上形成组合变化;4.形象整体同一律,即思维要素相互贯通、彼此融合,以形成整体的思维形象。 相似文献
16.
It is known by entropy theory that image is a source correlated with a certain characteristic of probability. The entropy rate of the source and ? entropy (rate-distortion function theory) are the information content to identify the characteristics of video images, and hence are essentially related with video image compression. They are fundamental theories of great significance to image compression, though impossible to be directly turned into a compression method. Based on the entropy theory and the image compression theory, by the application of the rate-distortion feature mathematical model and Lagrange multipliers to some theoretical problems in the H.264 standard, this paper presents a new the algorithm model of coding rate-distortion. This model is introduced into complete test on the capability of the test model of JM61e (JUT Test Model). The result shows that the speed of coding increases without significant reduction of the rate-distortion performance of the coder. 相似文献
17.
边缘的提取在人脸识别技术中具有重要的意义。传统的算法检测到的边缘信息往往是不完整的,而且在检测噪声污染图像时会得到许多虚假的边缘;而神经网络算法由于没有样本的压缩功能,导致训练量过大。文章在传统算法的基础上结合神经网络算法对人脸图像的边缘进行检测。实验结果表明,该方法快速稳定,得到的边缘图像边界封闭性好,抗噪能力强。 相似文献
18.
Autofocus method based on the analysis of image content information is investigated to reduce the alignment error resulting from mark positioning uncertainty due to defocus in microstructure layered fabrication process based on multilevel imprint lithography, The applicability of several autofocus functions to the alignment mark images is evaluated concerning their uniformity, sharpness near peak, reliability and measure computation efficiency and the most suitable one based on power spectrum in frequency domain (PSFD) is adopted. To solve the problem of too much computation amount needed in PSFD algorithm, the strategy of interested region detection and effective image reconstruction is proposed and the algorithm efficiency is improved. The test results show that the computation time is reduced from 0.316 s to 0.023 s under the same conditions while the other merits of the function are preserved, which indicates that the modified algorithm can meet the mark image autofocusing require-ments in response time, accuracy and robustness. The alignment error due to defocus which is about 0.5 μm indi-cated by experimental results can be reduced or eliminated by the autofocusing implementation. 相似文献
19.
An integrated and reliable phase unwrapping algorithm is proposed based on residues and blocking-lines detection, closed contour extraction and quality map ordering for the measurement of 3D shapes by Fourier-transform profilometry （FTP）. The proposed algorithm first detects the residues on the wrapped phase image, applies wavelet analysis to generate the blocking- lines that can just connect the residues of opposite polarity, then carries out the morphology operation to extract the closed contour of the shape, and finally uses the modulation intensity information and the Laplacian of Gaussian operation of the wrapped phase image as the quality map. The unwrapping process is completed from a region of high reliability to that of low reliability and the blocking-lines can prevent the phase error propagation effectively. Furthermore, by using the extracted closed contour to exclude the invalid areas from the phase unwrapping process, the algorithm becomes more efficient. The experiment shows the effectiveness of the new algorithm. 相似文献
20.
基于并行粒子群算法的Otsu双阈值医学图像分割 总被引：1，自引：0，他引：1
医学图像分割一直是医学影像分析领域的研究热点。由于粒子群优化(PSO)容易陷入局部极小,因此该算法用于搜索某些函数极值时精确度较低且稳定性较差。针对该问题,结合Otsu分割技术,提出了一种基于并行粒子群优化算法的Otsu双阈值医学图像分割算法。在该算法中,将粒子群体分成若干个子群体,进化在多个不同的子群中并行进行,避免单种群进化过程中出现的过早收敛现象,提高整个算法的收敛速度。实验结果表明,提出的分割算法与传统粒子群算法相比,不仅能够对图像进行准确的分割,而且具有更强的精确性和稳定性,其收敛速度明显优于基于单种群的粒子群算法的Otsu双阈值医学图像分割。 相似文献