The present invention is directed to a method for generating virtual image data at high resolution which is obtained when imaging is performed using a light ray incident on an imaging apparatus at a virtual position different from the actual position of an image sensor. A method for image processing includes acquiring light ray information, inputting virtual position information, generating first virtual image data which is obtained if the light ray is imaged at the virtual position with first resolution based on the light ray information and the virtual position information and inputting high resolution image data with second resolution higher than the first resolution, and generating second virtual image data which is obtained if the light ray is imaged at the virtual position with third resolution higher than the first resolution, based on the first virtual image data and the high resolution image data.