1. An image-sensing apparatus comprising: an image sensor which sequentially acquires source images by sequential shooting; an optical zoom control portion which varies a size of a subject image on the source images by optical zooming; a particular subject detection portion which detects a position and a size of a particular subject on the source images based on image data of the source images; a narrow-angle image extraction portion which sets, in each of the source images, a narrow-angle image including the particular subject based on a result of detection by the particular subject detection portion, to set a position and a size of the narrow-angle image on image; a wide-angle image extraction portion which extracts, from each of the source images, a wide-angle image that includes the narrow-angle image, that has a larger angle of view than the narrow-angle image, and that has a reference number of pixels; a resolution enhancement processing portion which cuts out, from a plurality of temporally consecutive wide-angle images, a plurality of narrow-angle images according to a setting in the narrow-angle image extraction portion, to generate, from the plurality of narrow-angle images, a narrow-angle high-resolution image having a number of pixels greater than a number of pixels of the narrow-angle image; and a recording portion which records image data of the individual wide-angle images, wherein the optical zoom control portion controls a factor of the optical zooming such that a ratio of the reference number of pixels to the number of pixels of the narrow-angle image approaches a factor of enlargement by the resolution enhancement processing portion.