In this paper, we eliminate the optical vignetting effect in refractive and reflective optical systems with image processing. We use the radiometric calibration method to obtain the calibration coefficient, which satisfies the quadratic polynomial distribution。The non-uniformity error before correcting is 13.2%, and it decreases to 3.8% after correcting, which demonstrates that the method of radiation correction could reduce the optical vignetting effect. In addition, in the real-time correction system, the quadratic polynomial fitting method greatly reduces the requirement of the correction coefficient on the storage resources. Compared with the original correction coefficient data size, the amount of stored data after fitting is reduced by about three orders of magnitude. The quadratic polynomial fitting method is able to effectively eliminate the optical vignetting effect, and it is easier to deploy in FPGA system, which is of great significance.