An image processing method and device is configured to convert an obtained image to be processed into a grayscale chrominance YUV mode image; determine an equilibrium mapping curve of a whole grayscale image according to the grayscale image in the YUV mode image; divide the whole grayscale image into a plurality of sub-regions, and determine a mapping restriction parameter for each pixel in each of the sub-regions; adjust a grayscale value of each pixel in the grayscale image according to the determined equilibrium mapping curve of the whole grayscale image and the mapping restriction parameter of each pixel in each of the sub-regions; and convert the adjusted grayscale image into an image of original mode. an image is processed using an equilibrium mapping curve and a plurality of mapping restriction parameters present the image details well and greatly reduce the calculation amount.