基于新型MRTD模型研究扫描型红外热像仪的视距

 基于人眼视觉系统可感知的阈值信噪比,提出预测红外热像仪最小可分辨温差（MRTD）方法。该方法根据频谱理论和红外热成像系统的二维调制传递函数,并结合匹配滤波器的概念,描述4条带标准靶的空间频谱函数。利用此空间频谱函数研究了4条带标准靶经过红外热成像系统的调制传递之后人眼视觉系统的感知信噪比。基于人眼视觉系统可感知的阈值信噪比,建立一个新的MRTD模型。依据此MRTD模型和视距模型,实现红外热像仪视距的预测。仿真结果表明,该方法预测的视距与实验数据有很好的一致性。     

近自然彩色图像融合算法及其实时处理系统的发展

在军事和生产领域,特别是在极其恶劣的可视条件下,图像融合技术越来越强调融合效果显示的"近自然"感觉,以及人类视觉感知的要求。从彩色图像融合算法的发展概况出发,着重介绍了两种具有代表性的基于视觉特性的近自然彩色图像融合方法,并特别阐述了课题组近期开展的相关算法研究成果。总结了国内外实时彩色图像融合系统的发展现状,概括了课题组已具备的硬件实验基础,综合分析了实时彩色图像融合技术的若干关键技术,如多源图像特征分析、实时图像配准、融合图像后处理等。针对实时图像融合技术的应用状况,提出图像融合系统未来的发展趋势。     

C波段全密封加速管研制

 介绍了一台1.5MeV的C波段便携式无损电子直线加速器的全密封加速管的设计、微波冷测和研制,热测结果表明该加速管满足加速器的设计要求。     

利用子波变换模拟人眼视觉信息提取过程的研究

由于人类视觉系统在对图象信息进行初级加工过程中表现出由粗到细且能使其局域化的特性,而子波变换恰恰正好具有这样的特性.本文提出了利用DOG函数作为子波基函数,模拟人眼视觉信息提取过程,并给出了两维模拟计算的结果.提出了基于子波变换理论的视觉信息提取通道模型.在文中讨论了这一模型的特点和潜在的应用前景.     

Review of in situ X-ray fluorescence analysis technology in China

In the past two decades, the in situ X-ray fluorescence (XRF) technology has been developed rapidly in China, which is mainly due to the rapid development of China's economy and the great demand for rapid qualitative and quantitative analysis of elements in geological exploration, environmental protection, and industrial process analysis. In this article, the development of in situ XRF analysis technology in China is reviewed from three aspects, namely in situ XRF analyzers, in situ XRF analysis technology, and applications of in situ XRF analysis technology. The in situ XRF analyzers are divided into four generations, and the technical characteristics of each generation of analyzers are discussed from the perspectives of X-ray excitation source, detector, electronic circuit unit, and digital signal processing. The progress of X-ray spectrum analysis, matrix effect correction, and correction of uneven effect and humidity effect is reviewed. The representative applications of XRF analysis technology in geological and mineral survey, environmental pollution investigation, cultural relic identification, and alloy analysis are introduced.     

Bifurcation analysis of visual angle model with anticipated time and stabilizing driving behavior

In the light of the visual angle model (VAM), an improved car-following model considering driver's visual angle, anticipated time and stabilizing driving behavior is proposed so as to investigate how the driver's behavior factors affect the stability of the traffic flow. Based on the model, linear stability analysis is performed together with bifurcation analysis, whose corresponding stability condition is highly fit to the results of the linear analysis. Furthermore, the time-dependent Ginzburg-Landau (TDGL) equation and the modified Korteweg-de Vries (mKdV) equation are derived by nonlinear analysis, and we obtain the relationship of the two equations through the comparison. Finally, parameter calibration and numerical simulation are conducted to verify the validity of the theoretical analysis, whose results are highly consistent with the theoretical analysis.     

亮度优化立体视频视觉舒适度评价

结合立体视频帧左右视图的灰度图,采用鲁棒性算法与软剪刀算法相结合的"画笔"方案来提取立体视频帧的前景区域,合成视差图并提取水平视差,计算深度视差;根据主观评价结果建立视差深度-视觉舒适度模型,再结合亮度对视觉舒适度的评价模型进行优化,使模型的评分更接近人类视觉系统的评分;结合人类主观评价实验的结果,用逆向代入法求出模型的系数确定模型,最终实现基于人类视觉系统特性的对立体视频视觉舒适度的评价。实验结果表明:通过视觉舒适度模型计算得到的结果与人类主观评价结果之间的误差率不超过5%,其中大部分视频误差率不超过1%。说明评价模型更符合人类主观感知结果的立体视频视觉舒适度,模型评分更接近人类视觉系统特性的主观实验评分,这为立体视频舒适度的评价提供了参考。     

Study on the Range of Particles Size Measured by Backscattering Method in Visual‐infrared Incident Spectrum

For the measurement of particles size with backscattering method, the suitable range of particles size measurement have been presented by independent algorithm in Visual‐infrared incident spectrum. We defined the range according to the retrieved results based on the analysis and comparison to many kinds of R‐R distribution function. The simulation computation results showed that the particles size measurement range is from 0.05 μm to 18 μm with incident spectrum from 0.4 μm to 2 μm and different refractive index. The results retrieved were satisfied even if 1 % noise was added into the backscattering intensity.     

基于智能手机的眼底成像系统

眼底成像技术可检测临床视网膜组织状态,其检测结果已成为多种眼底疾病诊断的重要依据。然而,传统的眼底成像系统需要专业医护人员操作,且具有体积大、价格昂贵等缺点。随着智能手机的图像采集、存储、数据传输等功能的不断提升,基于智能手机的眼底成像系统可有效弥补传统眼底成像系统的上述缺陷。在本研究中,我们设计了照明和成像光路并利用3D打印技术将其小型化,通过与智能手机相结合实现了对人眼视网膜图像的采集。结果表明,基于智能手机的眼底相机距离模拟眼的工作距离约为17 mm,安置于体积仅为88 mm×79 mm×42 mm(长×宽×高)的手机外设配件中。随后,利用Zemax对系统光学参数进行了进一步优化。经优化后的成像系统,畸变保持在0. 2%范围内,场曲小于10μm。该系统具有便携性良好、无创、价格低廉等优点,未来可用于多种眼底疾病的社区筛查工作。     

基于标志点识别的自主车视觉导航

提出了一种基于室内标志点识别的单目视觉导航的方法。在地面上有规律地旋转一些标志点,采用辅助先验知识对标志点进行识别和分割,利用透视投影变换得到标志点与摄像机之间的相对距离,达到通过单目摄像机获得景物深度信息的目的。整个算法结构简单,易于实现,对由照明不均匀和地面反光所引起的各种干扰有较好地抑制作用。