An endoscope apparatus, a program, and the like make it possible to display a display image in time series while reducing the defocus amount to achieve an in-focus state without increasing the amount of noise. The endoscope apparatus includes an image acquisition section (image composition processing section (310)) that acquires a captured image in a zoom observation state in time series, the zoom observation state being an observation state in which a magnification of an optical system is higher than that in a normal observation state, a defocus amount information extraction section (texture extraction section (320)) that extracts defocus amount information from the captured image in the zoom observation state, and a defocus amount correction section (texture correction amount calculation section (340), texture correction section (360), and blending section (370)) that corrects the captured image based on the extracted defocus amount information.
