Image noise grading method and device, readable storage medium and terminal equipment

The invention belongs to the technical field of image processing, and particularly relates to an image noise grading method and device, a computer readable storage medium and terminal equipment. The method comprises the following steps: acquiring a to-be-processed target image; extracting each noise feature of the target image; matching each noise feature of the target image in a preset noise base library to obtain a noise base expression matrix of the target image; wherein the noise base library comprises noise bases collected in advance, and each noise base corresponds to one type of noise features; determining the noise level of the target image according to a preset noise level mapping relation and the noise-based expression matrix of the target image; wherein the noise level mapping relation is a mapping relation between the noise base expression matrix and the noise level. According to the invention, based on the preset noise base library and the noise level mapping relation, the noise level of the imag