共查询到17条相似文献,搜索用时 187 毫秒
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提出了一种基于成像系统物理特性的多光谱图像与全色波段图像融合算法。该算法采用àtrous小波变换提取全色波段图像的空间细节信息,并将提取的空间信息按照一定的注入模型调整后添加到各波段多光谱图像中去,得到具有高空间分辨力的多光谱图像。注入模型充分考虑了各波段成像传感器的相对光谱响应函数、地表物体对各波段的光谱反射率以及各波段的辐射调整系数等成像系统的物理特性,使融合后的多光谱图像在显著提高空间质量的同时,最大可能地保留了原始多光谱图像的光谱特性。对IKONOS卫星遥感影像的融合实验结果表明,该算法在光谱保留和空间质量提高方面较其它基于小波变换的融合算法都具有更高的性能。 相似文献
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针对星载可见光相机成像模拟在逼真度和灵活性方面的综合仿真应用需求,研究并提出了一种以三维场景为基础,以光线追踪技术为主要渲染核心,综合考虑卫星轨道和姿态、光照条件、物体光谱特性和周边环境、大气传输、遥感器成像性能等影响因素的全光路成像模拟技术的仿真模型.文中首先从完备性及可扩展性的角度尝试建立了成像仿真系统的综合模型框架,对整个成像链中的各个重要环节进行分层及模块化,并结合目前现有三维技术、光线追踪技术、传感器仿真技术的特点设计各模块之间的调用及接口关系,使其能在较好利用现有计算模型的同时能够对新的算法模型实现有效兼容.随后讨论了模型目前使用的镜头前辐亮度计算模块、光线路径计算模块和传感器效果仿真模块,并针对简单空间探测场景用C++编程语言实现了系统框架和关键模型,生成模拟图像,结果证明该模型在深空光照及大气效果方面有较好的表现,具备较高的仿真度和良好的适应性、扩展性,能够有效支撑卫星光学成像系统的指标论证、算法评估以及效能预估等应用. 相似文献
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通过对外场观测的红外图像进行反演,获取了目标的临界尺寸和目标与背景的平均温差.以热成像系统的测试最小可分辨温差曲线为基础,确定了反演目标表观温度对应的空间频率,并结合Johnson准则和目标传递概率函数建立了实测目标图像与热成像系统探测识别性能的数学模型.该应用技术在外场识别性能评估中避免了人员对红外靶标图像的主观判读,可建立起客观的外场红外系统性能评估模型.对外场实测热图像及数据进行了实验,计算结果表明该模型可以有效地对红外成像系统的探测识别性能进行评估. 相似文献
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匹配滤波器优化设计及在红外弱小点目标检测中的应用 总被引:2,自引:0,他引:2
针对红外传感器成像信噪比低且易受噪声、背景杂波干扰的问题,结合红外图像中点目标成像的特性,充分利用目标、背景杂波及噪声在空间域中的分布特性,进行空间匹配滤波器的优化设计.首先对红外点目标特性进行了分析,在此基础上进行一维匹配滤波器的优化设计,进而构建了优化设计的空间匹配滤波器.结合优化设计匹配滤波器、形态学背景抑制和自适应门限的红外弱小目标枪测算法由于充分考虑了红外点目标的衍射效应和目标与背景的灰度差异,使滤波过程智能地融入了目标和背景的特性,极大地提高了红外弱小目标的检测性能.实测数据验证表明,本检测算法对低信噪比(f<,SNR>≤2)的红外图像,在保证10<'-5>虚警概率前提下,检测概率不小于95%. 相似文献
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为有效评价凝视成像系统的性能,依据凝视红外成像系统对红外辐射信号的转换机理,建立了凝视红外成像系统信号响应模型;利用线性系统理论和采样理论对成像系统的传递甬数进行了分析建模;借助于三维噪声模型表征了系统的噪声特性。以成像系统建模为基础,模拟生成不同尺寸、不同辐射温差的等边三角形方位靶标图像;针对不同刺激强度的三角形靶标仿真图像,统计观察者对靶标方向正确鉴别的概率,引入视觉心理测量函数——韦布尔(Weihull)函数拟合观察者鉴别概率数据,实现了三角方向鉴别阈值(TOD)曲线的预测。与实际测量结果进行比较,显示了此方法预测三角方向鉴别阈值曲线的合理性。 相似文献
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Infrared imaging simulation technology can provide infrared data sources for the development, improvement and evaluation of infrared imaging systems under different environment, status and weather conditions, which is reusable and more economic than physical experiments. A real-time infrared imaging simulation process is established to reproduce a complete physical imaging process. Our emphasis is put on the modeling of infrared sensors, involving physical effects of both spatial domain and frequency domain. An improved image convolution method is proposed based on GPU parallel processing to enhance the real-time simulation ability with ensuring its simulation accuracy at the same time. Finally the effectiveness of the above methods is validated by simulation analysis and result comparison. 相似文献
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Real-time infrared simulation technology can provide a large number of infrared images under different conditions to support the design, test and evaluation of a system having infrared imaging equipment with very low costs. By synthesizing heat transfer, infrared physics, fluid mechanics and computer graphics, a real-time infrared simulation method is proposed based on the method of characteristics to predict the infrared feature of aircraft plumes, which tries to obtain a good balance between simulation precision and computation efficiency. The temperature and pressure distribution in the under-expansion status can be rapidly solved with dynamically changing flight statuses and engine working states. And a modified C–G (Curtis–Godson) spectral band model that combines the plume streamlines with the conventional C–G spectral band model was implemented to calculate the non-uniformly distributed radiation parameters inside a plume field. The simulation result was analyzed and compared with the CFD++, which validates the credibility and efficiency of the proposed simulation method. 相似文献
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针对多通道数模转换电路输出不一致性问题,将两点非均匀性校正算法引入到不一致性问题中,提出了一种不一致性两点校正模型。通过分析红外探测器模拟器输出信号的样本数据,获得不一致性校正因子,并在现场可编程门阵列核心处理器中实现了该不一致性校正模型。利用红外探测器模拟器模拟320×256中波红外制冷探测器的输出信号,获得不一致性校正前后的图像。通过比较分析表明:校正前图像列平均灰度最大起伏量为15,校正后为5,相对改善了约66.7%。 相似文献
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红外成像目标模拟器是红外成像半实物仿真系统中的关键组成部分,基于微机械技术发展起来的MOS电阻阵列是红外图像生成器的重要发展方向。其中红外图像生成的质量是设计和研制红外成像目标模拟系统需重点考虑的问题。多种原因导致电阻阵列具有一定的非均匀性,因此在使用之前必须对其进行非均匀性校正。结合实际应用,阐述了基于MOS电阻阵列的红外成像目标模拟器的非均匀性产生机理,建立红外目标模拟器的非均匀性修正数据库对红外目标模拟器的图像数据源进行校正和补偿,产生校正后的图像数据,完成对红外目标模拟器存在非均匀性的离线修正。 相似文献
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Xiao-rui Wang Jian-qi Zhang Zhuo-xiang Feng Fang-ming Hu 《International Journal of Infrared and Millimeter Waves》2004,25(11):1645-1656
The TOD (triangle orientation discrimination threshold) metric, as a promising sensor performance measure, is suitable for all types of thermal imaging systems and corresponds to the field performance very well. Since this method was proposed, a great progress has been made in some aspects, such as experimental validation, field performance, and TOD sensor performance model. However, what is still missing is a TOD curve prediction model similar to MRTD (minimum resolvable temperature difference) equation. Here, an equation-based TOD performance model was first developed focusing on staring thermal imagers. Specifically, spatial distribution of the triangle standard test pattern is described quantitatively. Resolution transfer characteristic of the staring infrared imagers is modeled with linear system theory, and system noise is characterized with the introduction of three-dimensional noise model. The modulation effect of overall subsystem of staring thermal imager on the non-periodic triangle standard pattern is analyzed. The matched filter idea is adopted to characterize quantitatively the spatial integration of the eye to signal and various noise components over the triangle pattern area, and the perceived signal-to-noise ratio of the staring thermal imager is derived. Then, the TOD performance theoretical model is established. Comparing with experimental results, this theoretical model gives reasonable prediction of the TOD performance curve of staring thermal imagers. Although more tests and modifications are required, these preliminary results suggest that this model can be developed into a model that predicts the TOD for all kinds of sensors. 相似文献