多输出CCD接缝校正

针对多输出CCD传感器成像存在接缝的问题,提出了一种基于延时积分（TDI）的校正方法。使用TDI的读出方式对均匀光源成像获得了具有亮度线性渐变的图像数据,建立了获得图像的行平均灰度和行曝光时间关系的模型,通过该模型对CCD每路输出特性进行拟合,校正了CCD多输出的不均匀性,解决了图像接缝问题,并在模拟前端（AFE）完成了校正过程。本方法仅使用一次成像过程,避免了辐照度调整精度对校正精度的影响。与传统的两点法和多点法（16点）相比,提出方法的输出非均匀性分别减少了2.428%和 1.052%,校正效果明显提高。实验显示：本方法校正精度高,实验工作量低,可以广泛用于多输出CCD的接缝校正中。

Correction of seams for multiple output CCD

A new correction method based on the concept of Time Delay Integration (TDI) was proposed to eliminate the picture seams from a multiple output CCD. The TDI readout operation was used to capture the image under the illumination of a uniform light source, then a model to obtain the relationship between the line average gray level and the exposure time of the image was established. On the basis of the model, CCD output responses were fitted and the output non-uniformity was corrected. By the correction operations mentioned above, the seam correction was implemented in the analog domain of an Analog Front End (AFE).As only one image was needed for the correction method, the correction accuracy could not be affected by the illumination adjustment accuracy of uniform light source. Experiment results show that output non-uniformity by proposed method is 2.482% less than that of two-point method and 1.052% less than that of multi-point method (16 points), which means that the method has better correction effect, less experimental workload and can be widely used in the seam correction of multiple output CCDs.