1. An image forming device, comprising: a plurality of first light emitters that illuminate a subject with first illumination light beams polarized in a first direction; a plurality of second light emitters that illuminate the subject with second illumination light beams polarized in a second direction crossing the first direction; an imaging device having an imaging surface including a first area, which receives first reflection light beams polarized in the first direction, and a second area, which receives second reflection light beams polarized in the second direction; and an image forming circuit that forms an image of the subject on the basis of a first polarized image relating to the first reflection light beams, a second polarized image relating to the second reflection light beams, a third polarized image relating to the first reflection light beams, and a fourth polarized image relating to the second reflection light beams, the first polarized image and the second polarized image being captured by the imaging device while the subject is illuminated with the first illumination light beams, and the third polarized image and the fourth polarized image being captured by the imaging device while the subject is illuminated with the second illumination light beams, wherein a centroid of a geometric shape connecting positions of the plurality of first light emitters coincides with a centroid of a geometric shape connecting positions of the plurality of second light emitters, wherein the image forming circuit forms an image of the subject from a translated first polarized image, a translated second polarized image, a translated third polarized image, and a translated fourth polarized image, which are obtained from images of a plurality of first bright spots and images of a plurality of second bright spots, the first bright spots appearing on the first polarized image when the first illumination light beams are mirror-reflected off the subject, and the second bright spots appearing on the fourth polarized image when the second illumination light beams are mirror-reflected off the subject, and wherein the image forming circuit forms an image of the subject by calculating a difference between a first average image and a second average image, the first average image being obtained by averaging the translated first polarized image and the translated fourth polarized image, the second average image being obtained by averaging the translated second polarized image and the translated third polarized image.