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A light field modulated imaging spectrometer(LFMIS) can acquire the spatial-spectral datacube of targets of interest or a scene in a single shot. The spectral information of a point target is imaged on the pixels covered by a microlens.The pixels receive spectral information from different spectral filters to the diffraction and misalignments of the optical components. In this paper, we present a linear spectral multiplexing model of the acquired target spectrum. A calibration method is proposed for calibrating the center wavelengths and bandwidths of channels of an LFMIS system based on the liner-variable filter(LVF) and for determining the spectral multiplexing matrix. In order to improve the accuracy of the restored spectral data, we introduce a reconstruction algorithm based on the total least square(TLS) approach. Simulation and experimental results confirm the performance of the spectrum reconstruction algorithm and validate the feasibility of the proposed calibrating scheme. 相似文献
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The snapshot image mapping spectrometer(IMS) has advantages such as high temporal resolution,high throughput,compact structure and simple reconstructed algorithm.In recent years,it has been utilized in biomedicine,remote sensing,etc.However,the system errors and various factors can cause cross talk,image degradation and spectral distortion in the system.In this research,a theoretical model is presented along with the point response function(PRF) for the IMS,and the influence of the mirror tilt angle error of the image mapper and the prism apex angle error are analyzed based on the model.The results indicate that the tilt angle error causes loss of light throughput and the prism apex angle error causes spectral mixing between adjacent sub-images.The light intensity on the image plane is reduced to 95%when the mirror tilt angle error is increased to ±100 "(≈ 0.028°).The prism apex error should be controlled within the range of 0-36"(0.01°)to ensure the designed number of spectral bands,and avoid spectral mixing between adjacent images. 相似文献
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研究分析腹部超声联合动态对比增强磁共振成像(DCE-MRI)在卵巢瘤样病变中的诊断灵敏性,以临床疑似卵巢瘤样病变患者为研究对象,所有患者术前均行腹部超声联合DCE-MRI检查,以术后病理结果为“金标准”,探究腹部超声联合DCE-MRI的阳性与阴性检出结果,对比腹部超声联合DCE-MRI的诊断效能(特异度、敏感度),同时比较腹部超声联合DCE-MRI检查的阻力指数(RI),使用配套软件自动计算容量转移常数(Ktrans)、速率常数(Kep)及血管外细胞外间隙容积比(Ve),作受试者操作特征(ROC)曲线分析模型诊断价值。结果发现,腹部超声联合DCE-MRI诊断的敏感度(96.77%)、特异度(98.55%)均高于单一腹部超声及DCE-MRI诊断结果(P<0.05);卵巢瘤样病变组RI指数高于卵巢肿瘤组,Ktrans、Kep、Ve水平低于卵巢肿瘤组(P<0.05);绘制ROC曲线预测模型最佳临界值为0.088,提示腹部超声联合DCE-MRI在卵巢瘤样病变中的诊断综合价值高。 相似文献
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对甲氧基苯磺酰氯柱前衍生生物胺的高效液相色谱分离 总被引:1,自引:0,他引:1
采用对甲氧基苯磺酰氯作为柱前衍生试剂,RP-HPLC为分析模式,建立了一种新的生物胺衍生化方法,并对葡萄酒中生物胺含量进行检测。通过液质联用对产物进行定性,研究并确定了最适衍生化条件:衍生温度50℃,缓冲液pH 9.0,衍生时间15 min。实验建立了7种生物胺的HPLC分离方法:Beckman ODS柱;流动相A为10 mmol/L的NH4Ac溶液(pH 6.37),B相为乙腈;采用梯度洗脱;流速1 mL/min;检测波长240 nm,室温。 相似文献
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多帧图像超分辨率算法利用图像间的互补信息, 可以从一系列具有亚像素位移的低分辨率影像数据中重建出高分辨率图像. 在众多超分辨率算法中, 正则化方法以其求解病态问题的有效性而被广泛应用, 但在此类方法中, 最优估计算子的估计准确度对最后的重建结果有着较大的影响. 本文在现有正则化超分辨率重建算法的基础上, 提出了一种基于双阈值Huber范数的极大似然估计算子, 可以提高Huber范数对于阈值取值的容忍性和算子估计精度; 并给出了基于该算子的正则化超分辨率算法的迭代公式. 通过对仿真图像进行重建, 结果表明算法可有效地抑制各种噪声并保证重建效果; 同时将此算法应用于实际图像的超分辨率重建, 有效地提高了目标影像的空间分辨率.
关键词:
图像处理
图像重建
超分辨率
正则化 相似文献
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