CCD nonuniformity adaptive correction method based on empirical mode decomposition

In the high-precision measurement system, the charge coupled device (CCD) nonuniformity will give a greater margin of error to measurement results. According to the characteristic of noise leading to the image pixels nonuniformity, the corresponding image model is established. According to the traditional two-point linear correction method, an adaptive correction method is put forward, in which the Hilbert-Huang (HHT) filter theory is applied. With the scale decomposition of image sequences on the time domain and the corresponding statistics calculation, the offset and gain coefficients in CCD image are obtained. In experiments the high speed area array CCD is adopted to acquire images with the circular facula launched by the laser, and the algorithm is verified by calculating the facula central coordinates of the image. The results show that the algorithm can correct pixel nonuniformity effectively. The algorithm proposed is better than the algorithm for nonuniformity correction using linear model. The experimental result shows the superiority of the algorithm.