Down-sampling method and device for image

The embodiment of the invention provides an image down-sampling method and device, and relates to the technical field of image processing. The method comprises the following steps: acquiring a target image and a down-sampling rate; determining a down-sampling interval to which the down-sampling rate belongs; when the down-sampling rate belongs to a first down-sampling interval, down-sampling the target image by using a first down-sampling algorithm; when the down-sampling rate belongs to a second down-sampling interval, down-sampling the target image by using a second down-sampling algorithm; the second down-sampling interval is larger than the first down-sampling interval; the performance overhead of the second down-sampling algorithm is greater than that of the first down-sampling algorithm; under the condition of the same down-sampling rate, the image quality of the down-sampling image obtained by the second down-sampling algorithm is stronger than that of the down-sampling image obtained by the first down