异形孔径光阑成像系统像方空间光强分布计算

基于异形孔径光阑的成像系统像方光强分布计算对显微系统自动对焦、景深扩展等成像技术领域发展有极其重要的理论价值,而传统的菲涅耳衍射光强分布计算公式仅适用于轴对称孔径光阑,且在焦平面处光强分布的问题.利用标量衍射理论,通过结合频谱变换与正交分离,推导出适用于异形孔径形状、任意离焦量的像方空间光场强度分布数理关系式;并利用离散傅里叶变换原理,获得了基于异形孔径光阑的光学成像系统像方空间光强分布的数值计算表达式.在圆形孔径光阑、焦平面处,对获得的表达式与传统计算公式进行了对比计算与分析,两组计算结果完全一致.针对半圆形孔径光阑,在相同的系统参数下,在离焦量分别为0,4,8μm三个像方位置处,数理模型理论计算的结果与实验测试结果基本一致.从而证明所推导数理模型的准确性,其可适用于任意形状的孔径光阑.

Multi-Embed Nonlinear Scale-Space for Image Trust Root Generation

An image trust root is a special type of soft trust root for trusted computing. However,image trust root generation is difficult,as it needs a corresponding stable logic feature generation model and algorithm for dynamical and sustained authentication. This paper proposes a basic function of constructing new scale-spaces with deep detecting ability and high stability for image features aimed at image root generation. According to the heat distribution and spreading principle of various kinds of infinitesimal heat sources in the space medium,a multi-embed nonlinear diffusion equation that corresponds to the multi-embed nonlinear scale-space is proposed,a HARRIS-HESSIAN scale-space evaluation operator that aims at the structure acceleration characteristics of a local region and can make use of image pixels' relative spreading movement principle was constructed,then a single-parameter global symmetric proportion(SPGSP) operator was also constructed. An authentication test with 3000 to 5000 cloud entities shows the new scale-space can work well and is stable,when the whole cloud has 5%-50% behavior with un-trusted entities. Consequently,it can be used as the corresponding stable logic feature generation model and algorithm for all kinds of images,and logic relationships among image features for trust roots.

Electromagnetic fields from a horizontal electrical dipole buried in ocean

Marine controlled source electromagnetic signal could be used in mineral resource exploration,reservoir appraisal and communicative technique in ocean. It's necessary to study the electromagnetic generated by MCSEM. The propagation of the electromagnetic fields from a controlled source in the marine environment was studied with virtual interface method combined with discrete complex image method. Transmitter of finite length current source is approximated by dipole (HED) . A three-layered model is accepted,with sea water as intermediate conductive layer under air and a relatively high resistive seabed as basement,possibly containing a hydrogen layer of higher resistivity. The electromagnetic fields in whole space thus computed show that: (1) the spatial distribution of field component depends on its type; (2) inline Ex component is more sensitive to reservoir layer than that in broadside; (3) The airwave affects marine electromagnetic (MEM) exploration when sea water is relatively shallow; in the case of deep water MEM exploration,the airwave influence could be neglected; and (4) an appropriate frequency should be selected in order to balance the signal strength and electromagnetic induction effect.

A variation pixels identification method based on kernel spatial attraction model and local entropy for robust endmember extraction

A variation pixels identification method was proposed aiming at depressing the effect of variation pixels, which dilates the theoretical hyperspectral data simplex and misguides volume evaluation of the simplex. With integration of both spatial and spectral information, this method quantitatively defines a variation index for every pixel. The variation index is proportional to pixels local entropy but inversely proportional to pixels kernel spatial attraction. The number of pixels removed was modulated by an artificial threshold factor α. Two real hyperspectral data sets were employed to examine the endmember extraction results. The reconstruction errors of preprocessing data as opposed to the result of original data were compared. The experimental results show that the number of distinct endmembers extracted has increased and the reconstruction error is greatly reduced. 100% is an optional value for the threshold factor α when dealing with no prior knowledge hyperspectral data.

A new projection model based robust 2D-3D registration method on Fourier-Mellin space for image guided intervention

An automatic method is proposed to solve the registration problem,which aligns a single 2D fluoroscopic image to a 3D image volume without demanding any additional media like calibration plate or user interactions.First,a mathematic projection model is designed which can reduce the influence of projection distortion on parameter optimization and improve the registration accuracy.Then,a two stage optimization method is proposed,which enables a robust registration in a wide parameter space.Furthermore,an automatic registration framework is proposed based on the FourierMellin robust image comparison descriptor.Experimental results show that the registration method has a high accuracy with average rotation error of 0.6 degree and average translation error of 1.4mm.

The theory of information images： Modeling based on diffusion equations

This work represents a formalized description of information and communicative interac- tions of individuals on the basis of theory of information images （II）. It also demonstrates how important it is to choose the models type adequate to the systems under research. It also introduces an explication of the possibility to create the model of information and communication interactions that can illustrate transmission of information between two and more individuals. Methods and approaches suggested in this paper allow us to compare different levels of the described processes depending on the chosen architecture of the model; the methods and approaches mentioned in the current work can be also used to simulate the processes of distortion and generation of information images while information and communication social interaction. Expansion and addition of informa- tion images theory in terms of transmission of information among individuals enables us to speak about the space of individual II. The existence of such a space and creation of correct formalized model help us to explain a number of characteristic phenomena of human thinking processes. As a result of this research, the authors introduce an equa- tion that describes the spatial and structural evolution of individual II. There is also an example of modeling on the basis of this theory taking into account the results of the experiment （bilingual Stroop test）.