干涉型计算层析成像光谱仪的图像重建

针对干涉型计算层析成像光谱仪(CTII)提出了一种光谱图像数据立方体的重建方法。干涉型计算层析成像光谱仪是一种将空间调制傅里叶变换成像光谱仪(FTIS)的原理与计算层析成像光谱仪(CTIS)的原理相结合的一种新型成像光谱仪,具有高通量、高光谱分辨力以及高空间分辨力的特点。分析和讨论了干涉型计算层析成像光谱仪的工作原理以及获取图像的特征,介绍了光谱图像数据立方体的重建方法。根据多角度投影数据的特点提出采用卷积反投影计算层析成像图像重建算法,给出了图像重建步骤以及相应的数学表达式。对D65光源照明条件下的396×396像素目标进行了仿真实验,投影角度为0~180°,步长为0.5°,列出了仿真实验部分结果。实验结果验证了干涉型计算层析成像光谱仪及其图像重建算法的可行性。

Image Reconstruction for the Computed-Tomography Imaging Interferometer

An algorithm of image spectral data cube reconstruction for the computed-tomography imaging interferometer (CTII) is presented. Computed-tomography imaging interferometer combines advantages of both conventional spatially modulated Fourier transformation imaging spectrometer (FTIS) and computed-tomography imaging spectrometer (CTIS) such as high through put, high spectral resolution and high spatial resolution. The working principle of computed-tomography imaging interferometer and the characteristics of the images acquired form computed-tomography imaging interferometer are analyzed, and the method of data cube reconstruction is given. The convolution back-projection (CBP) is used in computed-tomography (CT) reconstruction, which is suitable for multiangular projection. The steps of image reconstruction and corresponding mathematical expression are introduced in detail. The simulations are carried out under the illumination of D65, a target of 396×396 pixels is projected at the range of 0～180°, and the projection interval is 0.5°. Part of the reconstructed images is displayed. The experimental results prove that the method is feasible.