1. An imaging apparatus comprising: an imaging portion that images an omnidirectional subject on the basis of an imaging position when imaging is performed and generates a circular image including the omnidirectional subject; an image processing portion that specifies a substantially fan-shaped object region in a circular image which is generated on the basis of a direction specified based on an attitude of an imaging apparatus in the imaging position among all directions and converts an image of the object region into a substantially rectangular image; and a display control portion that simultaneously displays a conversion image which is the converted image and the generated circular image on a display portion, in which in specifying the object region and converting the image of the object region the image processing portion (i) divides the generated circular image in a circumferential direction into four divided regions by use of first and second cutting lines in which the first cutting line corresponds to the specified direction and the second cutting line corresponds to a perpendicular direction thereto and in which the first and second cutting lines are rotated 45 degrees and in which the generated circular image is divided along the rotated first and second cutting lines so as to obtain four equally divided regions as the four divided regions, (ii) specifies the four divided regions as four object regions, and (iii) converts each respective image of the four object regions into a respective substantially rectangular conversion image.