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为了量化评价光学低通滤波器(optical low pass filter,OLPF),利用调制传递函数(modulation transfer function, MTF)建立了一个包含OLPF的二维数字光学成像系统模型,并以此模型为基础构建了OLPF的评价函数.应用该评价函数,计算三种典型OLPF的滤波特性,计算结果表明随着理想光学系统空间截止频率的增大,三种OLPF的滤波性能均有先微弱增强,后迅速减弱的趋势;当光学系统F数大于44时,采用嵌入“两层四点”式OLPF的数字成像系统的低通
关键词:
光学低通滤波器
调制传递函数
评价函数
空间频率 相似文献
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We propose a new subdivision technique directly subdividing the grating stripe by using complementary metal-oxide semiconductor (CMOS) microscopic imaging system combined with image processing. The corresponding optical system, subdivision principle, and image processing methods are illuminated. The relations of systemic resolution to subdivision number, grating period, magnifying power and tilt angle are theoretically discussed and experimentally checked on the Abbe comparator. The measurement precision for displacement of the proposed subdivision system is tested in the range of 5 mm and the maximum displacement error is less than 0.4μm. The factors contributing to the systemic error are also discussed. 相似文献
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Nonlinear effect of the structured light profilometry in the phase-shifting method and error correction 下载免费PDF全文
Digital structured light (SL) profilometry is increasingly used in three-dimensional (3D) measurement technology. However, the nonlinearity of the off-the-shelf projectors and cameras seriously reduces the measurement accuracy. In this paper, first, we review the nonlinear effects of the projector-camera system in the phase-shifting structured light depth measurement method. We show that high order harmonic wave components lead to phase error in the phase-shifting method. Then a practical method based on frequency domain filtering is proposed for nonlinear error reduction. By using this method, the nonlinear calibration of the SL system is not required. Moreover, both the nonlinear effects of the projector and the camera can be effectively reduced. The simulations and experiments have verified our nonlinear correction method. 相似文献
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光敏树脂固化机理研究 总被引:5,自引:0,他引:5
本文探讨了高新技术──快速成型技术中关键材料:光敏树脂的光固化机理。着重分析了光敏预聚物和光敏引发剂的光交联固化机理,并对光固化过程进行了讨论。 相似文献
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在轴角编码器的应用中 ,由于其基准元件的圆光栅副的工艺制作、参数 (尺寸、每周线数等 )及使用情况的不同 ,将对光电信号产生较大的影响。通过对三类线型的圆光栅副的理论计算和数据分析 ,图示了各类线型的圆光栅副在每个位置处的 (内径处、中径处和外径处 )透光强度 (即光电信号 )的相对变化 ,列表计算了等宽线条的圆光栅副在不同的每周线数值及中径处占空比不同时的各处光强的相对值 ,并由此推出了光电信号图形形状发生的变化。这些结论将对圆光栅副线型的设计、加工、调试和使用具有较大的参考价值 相似文献