Zernike矩不变性分析及其改进

在分析了Zernike矩不变性后,提出了一种基于图像整个区域形状描述算子的改进Zernike矩。改进的Zernike矩不仅具有旋转不变性,而且还具有改进前不具有的比例不变性。试验结果证明,和改进前的Zernike矩相比,改进后的Zernike矩具有更好的不变特征,可用作基于区域的形状描述算子。     

纹理图像检索的不同相似性度量方法的比较研究

图像特征和相似性度量方法的选取是基于内容图像检索的一个关键环节。针对该问题，提出一种基于整数小波包分解的纹理特征检索方法。通过连接小波包分解后各尺度内和尺度闯不同频带的小波系数，提取标准方差和均值信息描述纹理。此外，对8种相似性度量方法进行了分析和比较。通过对纹理库的检索实验表明，与传统的距离测度相比，Canberra和Bray—Curtis距离测度能有效地提高图像的检索性能。     

用小波包变换产生音频数据索引的方法

针对音频多媒体数据库中基于例子和基于内容的查询,本文提出一种产生音频数据索引的方法.这里,我们首先讨论了小波包分解的过程和最好基及代价函数的选择方法.其次,对现有的用小波变换产生音频数据索引的二个方法进行比较,并提出基于小波包最好基变换产生音频数据索引的方法.再次,我们提出用音频数据的小波包最好基变换系数的部分最高值的能量作为音频数据索引.最后,我们把这种方法与直接采用小波变换产生索引的方法相比较.实验结果表明这种新方法具有较高和较稳定的检索精度.     

Improving Nonlocal Means Method via a No-reference Image Content Metric for MRI Denoising

The patch matching of the traditional Nonlocal means （NLM） filter mainly depends on structure similarity and cannot adapt to the patch rotation or mirroring transformation. Therefore, designing a measure with rorationally invariant similarity is of significant importance for improving the effectiveness of patch comparison of NLM. This paper proposes to apply a no-reference image content metric with the rotation-invariance to NLM for denoising Magnetic resonance （MR） images. The metric measures quantitatively the content of a patch in an image, including sharpness, contrast, and geometric features such as textures and edges. The metric values for every patch are computed and added into the Gaussian matching kernel of NLM so as to effectively perform patch matching. The main advantage of the proposed method is that it does not need to rotate patches in different orientations during patch matching. Experimental results show that the proposed method is superior to the traditional NLM, the state-of-the-art method Block-matching and 3- D （BM3D） filtering and the Unbiased NLM （UNLM） for MRI denoislng.     

基于相对熵和K-means的形状相似差分隐私轨迹保护机制

为解决绝大多数研究未充分考虑位置对隐私预算的敏感程度以及轨迹形状带来的影响,使发布的轨迹可用性较差的问题,提出了基于相对熵和K-means的形状相似差分隐私轨迹保护机制.首先,根据地理空间的拓扑关系,利用相对熵计算真实位置对隐私预算的敏感程度,设计了位置敏感的隐私级别实时计算算法,并与差分隐私预算结合建立了一个新的隐私...     

基于相似度的变精度容差关系扩充粗糙集模型

比较分析了已有扩充粗糙集模型,提出基于相似度的变精度容差关系扩充粗糙集模型。该模型根据两对象的相似度及属性值缺失情况划分客差类。通过与基于容差关系、相似关系、限制容差关系等扩充粗糙集模型比较,证实了该模型对不完备信息系统处理的现实可行性和有效性,最后给出了相对正域的概念及属性约简规则。     

Software lens compensation applied to athermalization of infrared imaging systems

A different approach, aiming to achieve the constant blur status of point-spread function (PSF) at a certain defocused plane, is described. The correlation between the two PSF is used to control the PSF blur similarity, and simultaneously the Strehl ratio is also used to control the PSF blur minimization. By designing the PSF so that it is significantly insensitive to defocus or related defocus quantity, for example, due to temperature change, all the constantly blurred images can be accurately de-blurred by a simple inverse restoration filter for an adequate range of defocus. We refer to that as “software lens compensation” and apply a design method to solve the athermalization of middle wavelength infrared (MWIR) imaging systems. The resultant PSF is almost invariant in the temperature range from −10 to 50°C at the same focal plane. Consequently, the constant blur spot can be removed by a simple digital signal processing. Thus, clear and sharp de-blurred images at different temperatures are obtained.     

A two-stage shape retrieval (TSR) method with global and local features

A robust two-stage shape retrieval (TSR) method is proposed to address the 2D shape retrieval problem. Most state-of-the-art shape retrieval methods are based on local features matching and ranking. Their retrieval performance is not robust since they may retrieve globally dissimilar shapes in high ranks. To overcome this challenge, we decompose the decision process into two stages. In the first irrelevant cluster filtering (ICF) stage, we consider both global and local features and use them to predict the relevance of gallery shapes with respect to the query. Irrelevant shapes are removed from the candidate shape set. After that, a local-features-based matching and ranking (LMR) method follows in the second stage. We apply the proposed TSR system to MPEG-7, Kimia99 and Tari1000 three datasets and show that it outperforms all other existing methods. The robust retrieval performance of the TSR system is demonstrated.     

浅析图像领域PCT申请的补充检索

图像领域PCT申请通常存在丰富的已有信息,且技术方案复杂度较高.针对图像领域PCT申请补充检索的典型情况,给出了相应的补充检索策略,并通过实际案例验证了上述补充检索策略的有效性.审查员应灵活运用相应的补充检索策略,提高检索的有效性.     

国外互联网新业务信息安全管理对策

由于互联网新业务具有较强的不可预见性．因此对于互联网新业务发展中所带来的信息安全问题。互联网新业务种类不断翻新，从监管的视角出发，互联网新业务基本可以划分为三个大类：社区类、信息发布类和信息检索类。本文将分别介绍国外对社区类、信息发布类和信息检索类互联网新业务的管理对策。