Image quality evaluation method and device based on extended Prewitt operator

The invention provides an image quality evaluation method and device based on an extended Prewitt operator, and the method comprises the steps: obtaining a reference image and a to-be-evaluated distorted image; preprocessing the reference image and the distorted image, and determining a brightness factor and a contrast factor of the reference image and the distorted image; performing convolution operation on the reference image and the distorted image according to the extended Prewitt operator, and calculating a first gradient value corresponding to the reference image and a second gradient value corresponding to the distorted image; determining a gradient similarity factor of the reference image and the distorted image according to the first gradient value and the second gradient value; and determining an objective evaluation result of the image quality by combining the gradient similarity factor, the brightness factor and the contrast factor. According to the method, the defects of atraditional Prewitt oper