Nonlinear transformation image enhancement method

The invention discloses a non-linear change image enhancement method, which comprises the following steps of carrying out linear stretching on a gray value of an input image, and expanding a gray spectrum bandwidth to obtain a standardized image; calculating the mean value and the median value of the standardized image and the median value of the dynamic range occupied by the histogram of the standardized image, taking the mean value and the median value or the median value of the dynamic range occupied by the histogram of the standardized image as separation values, and dividing the standardized image into two regions according to the pixel size; calculating a pixel intensity average value of the two regions, and calculating power function parameters of the two regions according to the pixel intensity average value; correcting the corresponding regions by using the power function parameters to obtain two corrected sub-images; combining the two corrected sub-images to obtain a final enhanced image. The method