An image-taking system includes an image-taking device which takes an image of a subject; a flashing device which emits a flash to the subject; an illumination device which has a surface positioned opposite the image-taking device and which illuminates the subject interposed between the image-taking device and the surface with light emitted from the surface. The system further includes a background replacement device which acquires a plurality of images of the subject taken by the image-taking device under a respective plurality of image-taking-light conditions created by the flashing device and the illumination device, discriminates between the subject and a background in a taken image based on the acquired images, and replaces the background with another background.