一种高精度CCD测试系统的非均匀性校正方法

针对高精度光电耦合器件(CCD)测试系统中像素的非均匀性给测试结果带来较大误差的问题,根据引起图像像素非均匀性噪声的特性,建立了对应的图像模型.采用自适应阈值分割算法将图像二值化分离出有效使用像素,并提出了一种采用两点线性方法对非均匀性像素进行校正的算法.仿真实验采用高速面阵CCD采集由激光器发射的圆形光斑图像,并通过计算图像光斑的中心坐标进行了验证.结果表明,该算法能够将图像的复杂背景与光斑分离,可校正其像素的非均匀性,稳定光斑的像素灰度值.在相同条件下连续采集图像,图像光斑的中心坐标稳定.

Nonuniformity Correction Method in the High-Precision CCD Measurement System

In the high-precision measurement system, the CCD pixes nonuniformity will give a greater margin of error to measurement results. According to the characteristics of noise leading to the image pixels nonuniformity, this article establishes the corresponding image model. Adaptive threshold segmentation algorithm is used for image binarization and isolating the effective pixels. An algorithm using two points linear method for pixel non-uniformity correction is put forward. Experiments adopt the high speed area array CCD to gather images with the circular facula launched by the laser, and verify the algorithm by calculating the facula center coordinates of the image. The results showed that the algorithm can separate light intensity positions from the image, correct pixel nonuniformity, and stabilize pixel gray value of light intensity positions. Under the same conditions for image acquisition, the center coordinates of image light intensity positions stabilize.