视图的秘密分享是图像信息安全领域独具吸引力的研究问题。寻求秘密视图完全的(Perfect)和理想的(Ideal)门限秘密分享方案(也称图像门限分享的完备方案),则是其中富有挑战性的未决课题。文中引入灰度值域GF(2m)上像素矩阵秘密分享的新...视图的秘密分享是图像信息安全领域独具吸引力的研究问题。寻求秘密视图完全的(Perfect)和理想的(Ideal)门限秘密分享方案(也称图像门限分享的完备方案),则是其中富有挑战性的未决课题。文中引入灰度值域GF(2m)上像素矩阵秘密分享的新观点和相应的代数几何编码方法,实现了数字图像(t,n)门限秘密分享的一种完备方案。该方案能够将一幅或多幅秘密图像编码为n幅各具随机视觉内容,同时又共具(t,n)门限结构的影子图像(或称份额图像)。证明了这种秘密分享方案的(t,n)门限结构不仅是完全的而且也是理想的,并给出了提高像素灰度值域GF(2m)上图像秘密分享算法效率的"m位像素值的分拆与并行"方法。分析表明,该图像秘密分享方法可以应用于高安全等级的秘密图像的网络多路径传输、保密图像信息的分散式存储控制、高维图形码(Bar-code in k dimension)和弹出码(Popcode)等新一代信息载体技术的识读控制等各方面。展开更多
传统的Bag of Words模型检索方法并不具备局部特征间的空间关系,因此影响检索性能.本文提出了基于分级显著信息的空间编码方法.通过分层次的提取显著区域并对每个显著区域内的特征点进行空间编码.目的是探索特征间的空间关系,并根据分...传统的Bag of Words模型检索方法并不具备局部特征间的空间关系,因此影响检索性能.本文提出了基于分级显著信息的空间编码方法.通过分层次的提取显著区域并对每个显著区域内的特征点进行空间编码.目的是探索特征间的空间关系,并根据分级显著信息提高特征间的相关性.在几何验证过程中,本文通过任意三点间的角度编码和位移编码构成的空间编码方法完成图像对之间的空间关系匹配,同时根据图像各个区域间的显著程度赋予该区域空间关系匹配得分相应权重,得到最终的几何得分,重新排列检索结果.实验结果表明本文提出的方法既改善了最终检索结果的精确度又降低了几何验证阶段的计算时间.展开更多
Strongly regular (α,β)-reguli are a class of incidence structures with given conditions which were introduced by Hamilton and Mathon. We introduce two classes of codes constructed from strongly regular (α,β)-regul...Strongly regular (α,β)-reguli are a class of incidence structures with given conditions which were introduced by Hamilton and Mathon. We introduce two classes of codes constructed from strongly regular (α,β)-reguli within PG(k-1,q). The codes are related with two-weight codes intimately.展开更多
Discrete Global Grid Systems(DGGSs) are spatial references that use a hierarchical tessellation of cells to partition and address the entire globe. They provide an organizational structure that permits fast integratio...Discrete Global Grid Systems(DGGSs) are spatial references that use a hierarchical tessellation of cells to partition and address the entire globe. They provide an organizational structure that permits fast integration between multiple sources of large and variable geospatial data sufficient for visualization and analysis. Despite a significant body of research supporting hexagonal DGGSs as the superior choice, the application thereof has been hindered owing in part to the lack of a rational hierarchy with an efficient addressing system. This paper presents an algebraic model of encoding scheme for the Aperture 3 Hexagonal(A3H) DGGS. Firstly, the definition of a grid cell, which is composed of vertices, edges, and a center, is introduced to describe fundamental elements of grids. Secondly, by identifying the grid cell with its center, this paper proves that cell centers at different levels can be represented exactly using a mixed positional number system in the complex plane through the recursive geometric relationship between two successive levels, which reveals that grid cells are essentially special complex radix numbers. Thirdly, it is shown that through the recursive geometric relationship of successive odd or even levels, the mixed positional number system can also be applied to uniquely represent cell centers at different levels under specific constraint conditions, according to which the encoding scheme is designed. Finally, it is shown that by extending the scheme to 20 triangular faces of the regular icosahedron,multi-resolution grids on closed surfaces of the icosahedron are addressed perfectly. Contrast experiments show that the proposed encoding scheme has the advantages of theoretical rigor and high programming efficiency and that the efficiency of cross-face adjacent cell searching is 242.9 times that of a similar scheme. Moreover, the proposed complex radix number representation is an ideal formalized description tool for grid systems. The research ideas introduced herein can be used to create a universal theoretical framework for DGGSs.展开更多
This paper consider Hexagonal-metric codes over certain class of finite fields. The Hexagonal metric as defined by Huber is a non-trivial metric over certain classes of finite fields. Hexagonal-metric codes are applie...This paper consider Hexagonal-metric codes over certain class of finite fields. The Hexagonal metric as defined by Huber is a non-trivial metric over certain classes of finite fields. Hexagonal-metric codes are applied in coded modulation scheme based on hexagonal-like signal constellations. Since the development of tight bounds for error correcting codes using new distance is a research problem, the purpose of this note is to generalize the Plotkin bound for linear codes over finite fields equipped with the Hexagonal metric. By means of a two-step method, the author presents a geometric method to construct finite signal constellations from quotient lattices associated to the rings of Eisenstein-Jacobi （E J） integers and their prime ideals and thus naturally label the constellation points by elements of a finite field. The Plotkin bound is derived from simple computing on the geometric figure of a finite field.展开更多
文摘视图的秘密分享是图像信息安全领域独具吸引力的研究问题。寻求秘密视图完全的(Perfect)和理想的(Ideal)门限秘密分享方案(也称图像门限分享的完备方案),则是其中富有挑战性的未决课题。文中引入灰度值域GF(2m)上像素矩阵秘密分享的新观点和相应的代数几何编码方法,实现了数字图像(t,n)门限秘密分享的一种完备方案。该方案能够将一幅或多幅秘密图像编码为n幅各具随机视觉内容,同时又共具(t,n)门限结构的影子图像(或称份额图像)。证明了这种秘密分享方案的(t,n)门限结构不仅是完全的而且也是理想的,并给出了提高像素灰度值域GF(2m)上图像秘密分享算法效率的"m位像素值的分拆与并行"方法。分析表明,该图像秘密分享方法可以应用于高安全等级的秘密图像的网络多路径传输、保密图像信息的分散式存储控制、高维图形码(Bar-code in k dimension)和弹出码(Popcode)等新一代信息载体技术的识读控制等各方面。
文摘传统的Bag of Words模型检索方法并不具备局部特征间的空间关系,因此影响检索性能.本文提出了基于分级显著信息的空间编码方法.通过分层次的提取显著区域并对每个显著区域内的特征点进行空间编码.目的是探索特征间的空间关系,并根据分级显著信息提高特征间的相关性.在几何验证过程中,本文通过任意三点间的角度编码和位移编码构成的空间编码方法完成图像对之间的空间关系匹配,同时根据图像各个区域间的显著程度赋予该区域空间关系匹配得分相应权重,得到最终的几何得分,重新排列检索结果.实验结果表明本文提出的方法既改善了最终检索结果的精确度又降低了几何验证阶段的计算时间.
基金the Scientific Research Start-up Foundation of Qingdao University of Science and Technology in China (No. 0022327)
文摘Strongly regular (α,β)-reguli are a class of incidence structures with given conditions which were introduced by Hamilton and Mathon. We introduce two classes of codes constructed from strongly regular (α,β)-reguli within PG(k-1,q). The codes are related with two-weight codes intimately.
基金supported by the National Natural Science Foundation of China (Grant No. 41671410)the Postdoctoral Science Foundation of China (Grant No. 2013T60161)the Excellent Young Scholar Foundation of Information Engineering University (Grant No. 2016610802)
文摘Discrete Global Grid Systems(DGGSs) are spatial references that use a hierarchical tessellation of cells to partition and address the entire globe. They provide an organizational structure that permits fast integration between multiple sources of large and variable geospatial data sufficient for visualization and analysis. Despite a significant body of research supporting hexagonal DGGSs as the superior choice, the application thereof has been hindered owing in part to the lack of a rational hierarchy with an efficient addressing system. This paper presents an algebraic model of encoding scheme for the Aperture 3 Hexagonal(A3H) DGGS. Firstly, the definition of a grid cell, which is composed of vertices, edges, and a center, is introduced to describe fundamental elements of grids. Secondly, by identifying the grid cell with its center, this paper proves that cell centers at different levels can be represented exactly using a mixed positional number system in the complex plane through the recursive geometric relationship between two successive levels, which reveals that grid cells are essentially special complex radix numbers. Thirdly, it is shown that through the recursive geometric relationship of successive odd or even levels, the mixed positional number system can also be applied to uniquely represent cell centers at different levels under specific constraint conditions, according to which the encoding scheme is designed. Finally, it is shown that by extending the scheme to 20 triangular faces of the regular icosahedron,multi-resolution grids on closed surfaces of the icosahedron are addressed perfectly. Contrast experiments show that the proposed encoding scheme has the advantages of theoretical rigor and high programming efficiency and that the efficiency of cross-face adjacent cell searching is 242.9 times that of a similar scheme. Moreover, the proposed complex radix number representation is an ideal formalized description tool for grid systems. The research ideas introduced herein can be used to create a universal theoretical framework for DGGSs.
基金supported by 973 project under Grant No.2007CB807901the Fundamental Research Funds for the Central Universities under Grant Nos.YWFF-10-02-072 and YWF-10-01-A28
文摘This paper consider Hexagonal-metric codes over certain class of finite fields. The Hexagonal metric as defined by Huber is a non-trivial metric over certain classes of finite fields. Hexagonal-metric codes are applied in coded modulation scheme based on hexagonal-like signal constellations. Since the development of tight bounds for error correcting codes using new distance is a research problem, the purpose of this note is to generalize the Plotkin bound for linear codes over finite fields equipped with the Hexagonal metric. By means of a two-step method, the author presents a geometric method to construct finite signal constellations from quotient lattices associated to the rings of Eisenstein-Jacobi （E J） integers and their prime ideals and thus naturally label the constellation points by elements of a finite field. The Plotkin bound is derived from simple computing on the geometric figure of a finite field.
