1. An image processing method comprising: performing by a processor the following: designating a borderless printing mode; determining, from an original image, a printing region for actual printing performed on a recording medium, the printing region corresponding to a size of paper for recording, and determining an expanded region that is expanded outward from the printing region for borderless printing; discriminating whether or not the expanded region determined in said region determining step exceeds the original image; extrapolating, if the expanded region exceeds the original image, an image data for the expanded region based on copying image data of pixels from an end portion of the original image adjacent to the expanded region; forming data for printing based on the extrapolated image for the expanded region and the original image, wherein the image data is extrapolated for a part of the expanded region that exceeds the original image and the image data is not extrapolated for a part of the expanded region that does not exceed the original image.