An interpolation processing method for performing interpolation processing
of image data obtained by photoelectrically converting an object image
using interpolation data, includes a first step of estimating object
information, a second step of generating first input image data based on
the object information, a third step of generating first transformation
data from the first input image data to the image data, a fourth step of
generating second transformation data from the first input image data to
interpolated image data after the interpolation processing, and a fifth
step of generating the interpolation data using the first and second
transformation data.