An image processing method, adapted for an image processing device, wherein the image processing device comprises a processor and a storage unit, and according to instructions of the image processing device, characterized in that the image processing method executes steps as follows: receiving a plurality of image quality assessment, IQA, methods; calculating a total execution time of a cloud server for executing the image quality assessment methods, and calculating individual execution times of the image processing device for executing the image quality assessment methods; classifying the image quality assessment methods into first type of image quality assessment methods (IQA_G1) and second type of image quality assessment methods (IQA_G2) according to the individual execution times and the total execution time; and performing the first type of image quality assessment methods (IQA_G1) by the image processing device, and performing the second type of image quality assessment methods (IQA_G2) by the cloud server; wherein after the step of performing the first type of image quality assessment methods (IQA_G1) by the image processing device, and performing the second type of image quality assessment methods (IQA_G2) by the cloud server, the image processing method further comprises: using an image (Img_m) that has passed the second type of image quality assessment methods (IQA_G2) on image recognition by the cloud server, and outputting an image recognition result; and executing the first type of image quality assessment methods (IQA_G1) by the image processing device to output an execution result, and displaying the image recognition result on a display if the execution result is passed; but not using the image recognition result if the execution result is not passed. receiving a plurality of image quality assessment, IQA, methods; calculating a total execution time of a cloud server for executing the image quality assessment methods, and calculating individual execution times of the image processing device for executing the image quality assessment methods; classifying the image quality assessment methods into first type of image quality assessment methods (IQA_G1) and second type of image quality assessment methods (IQA_G2) according to the individual execution times and the total execution time; and performing the first type of image quality assessment methods (IQA_G1) by the image processing device, and performing the second type of image quality assessment methods (IQA_G2) by the cloud server; wherein after the step of performing the first type of image quality assessment methods (IQA_G1) by the image processing device, and performing the second type of image quality assessment methods (IQA_G2) by the cloud server, the image processing method further comprises: using an image (Img_m) that has passed the second type of image quality assessment methods (IQA_G2) on image recognition by the cloud server, and outputting an image recognition result; and executing the first type of image quality assessment methods (IQA_G1) by the image processing device to output an execution result, and displaying the image recognition result on a display if the execution result is passed; but not using the image recognition result if the execution result is not passed. using an image (Img_m) that has passed the second type of image quality assessment methods (IQA_G2) on image recognition by the cloud server, and outputting an image recognition result; and executing the first type of image quality assessment methods (IQA_G1) by the image processing device to output an execution result, and displaying the image recognition result on a display if the execution result is passed; but not using the image recognition result if the execution result is not passed.