An image processing method includes: performing coordinate conversion to determine that a final image is to be obtained by processing target rows of data of a source image, wherein the target rows of data of the source image are stored in an external storage device; reading, from the external storage device, the data of the target rows of the source image to an internal storage device; and processing the data of the target rows of the source image in the internal storage device to obtain the final image. The invention performs coordinate conversion to determine data to be cached, such that a data caching operation is independent from a size of a region to be padded, and resources of the internal storage device required are reduced.