图像模拟在白炽灯气体折射率全息CT测量中的应用

Application of Image Simulation to the Holographic CT Measurement for Refractive Index of the Gas in an Incandescence Lamp

简要介绍白炽灯点燃过程中灯内气体折射率三维分布测量的实时全息干涉图像,根据密闭气体被灯丝加热时所涉及的物理问题建立简化的物理及数学模型,并利用数字图像处理技术对全息干涉图像的形成过程进行模拟研究。研究结果表明,当灯泡外空间的折射率变化不均匀时,灯泡投影区域内的干涉图像将同时带有灯内外气体折射率变化的信息,利用干涉图像中灯泡投影区域外干涉条纹的测量结果可以对实际测量结果进行修正。此外,根据研究结果及全息CT技术,给出了忽略灯泡外空间的折射率变化影响时白炽灯内气体折射率三维分布测量的实例。

Real-time holographic interference patterns of three-dimensional distribution of gas refractive index in an incandescence lamp during its lighting process are introduced here briefly. Based on the fundamental physical problems occurred in gas heating process by filament, a concise physical and mathematical model has been developed. The forming processes of holographic interference pattern are studied numerically by using digital image processing technique. The obtained results have shown that when the refractive index outside of filament has a non-uniform distribution, the information of this non-uniform distribution can be reflected by the interference pattern in the projection of lamp, and the measurements of the fringes of interference pattern can be used to modify the real measurement data. Moreover, based on the result of study and the holographic computed tomography (CT) technique, an example of the three-dimension distribution of gas refractive index inside an incandescence lamp is given without the influence of the change of refractive index outside of the lamp.