1. A non-transitory computer-readable recording medium recording a program for image processing causing a computer to provide functionality comprising: a captured image acquisition that acquires a captured image captured by an imaging device; a display control that displays an image including the captured image on a display device; and a feature detection that detects, from the captured image, a feature in a real space captured in the captured image, using an image for detection of the feature, wherein when the captured image acquired by the captured image acquisition is a reversed image, the feature detection includes performance of a reverse comparison process to detect the feature, the reverse comparison process involving: comparing the captured image with a reversed image of the image for detection; or comparing an image obtained by further reversing the captured image, with the image for detection.