基于针孔目标物的调制传递函数测试

为了有效测试物镜或光学系统的调制传递函数，采用CCD自动扫描针孔像，并分析系统及环境对目标像的影响因素；系统通过连续采集多幅目标物图像进行平均后，再减去当时的背景图像进行图像处理，选取包含目标物所有信息的合适积分区域，然后通过子午和弧矢方向的积分得到一维的线扩散函数，再经数据处理后由离散傅里叶变换求模得到较可靠的调制传递函数。结果表明：该方法能够快速测量出被测物镜的调制传递函数。

MTF testing based on a pinhole target

In order to effectively evaluate the modulation transfer function of an objective or optical system, the pinhole image is scanned automatically by CCD, with consideration for the effects of the system and the environment on the pinhole image. The image processing for the system is performed by continuously collecting several pinhole images, averaging them and then subtracting their backgrounds from them. The proper integration area containing all target information is chosen, and the reliable MTF is achieved by deriving the one-dimensional line spread function from the integration in the meridian and sagittal directions and then performing the discrete Fourier Transform with the processed data. The resulting data indicate that the MTFs of objectives under test can be measured quickly and accurately in this way.