Research and Improvement of the Formula of Correlation Coefficient in Image Processing

The research of sub-pixel algorithm has always been a hot topic in the field of image processing. How to improve the accuracy of sub-pixel algorithm and reduce its error is difficult and difficult. This paper uses the digital speckle correlation method and the formula of the correlation coefficient of different powers to calculate the sub-pixel displacement of the image through MATLAB. The experimental results show that the higher-order formula is more stable and accurate than the lower-order formula. With the increase of the power, the error of the calculation result is smaller, and the error calculated by formula C15ZNCC is reduced by 21.66% than the error calculated by formula CZNCC. Studies have shown that by increasing the number of powers of the correlation coefficient calculation formula can reduce the error of the sub-pixel algorithm.