1. A portable terminal apparatus for transmitting image data to an image output apparatus, the image output apparatus including: a correction processing section for carrying out a high resolution correction in accordance with a plurality of pieces of the image data so as to obtain high resolution image data which has a higher resolution than the plurality of pieces of the image data, the image output apparatus outputting the high resolution image data corrected by the correction processing section, said portable terminal apparatus, comprising: an image capture section for consecutively more than once capturing images of an identical object; a captured image determination section for determining whether or not a plurality of pieces of captured image data captured by the image capture section meet a given requirement; and a transmission section for transmitting, to the image output apparatus, captured image data which is determined, by the captured image determination section, to meet the given requirement, the given requirement including a requirement A, the requirement A being such that the plurality of pieces of captured image data consecutively captured by the image capture section include a combination of a given number of pieces of captured image data which are applicable to be subjected to the high resolution correction by the correction processing section, with the given number of pieces of captured image data being an integer not less than 2, and the plurality of pieces of captured image data are offset by a given pixel amount, the transmission section transmitting the given number of pieces of captured image data which are determined to be the combination by the captured image determination section, wherein: the identical object whose images are captured has a rectangular plane on which a text image is formed; and the given requirement further includes a requirement B, the requirement B being such that features fall within a given range, the features indicative of a degree of a geometric distortion of the rectangular plane in the captured image data, the geometric distortion occurring when the image capture section captured image data obliquely with respect to a normal direction of the rectangular plane.