The present disclosure provides an image processing method and device, and a display device. The image processing method comprises: acquiring an image brightness information; obtaining a gray scale compensation parameter of at least two band points of each first sub-image area according to brightness information and reference brightness of the at least two band points comprised in the brightness information of each first sub-image area of the image brightness information; obtaining the gray scale compensation information of each first sub-image area according to the gray scale compensation parameters of the at least two band points; and compensating the gray scale of the image according to the gray scale information of the M of first sub-image areas.