1. An image pickup device for picking up images in a plurality of wavelength bands, comprising: a first image pickup part for picking up an optical image in a near-infrared band; a second image pickup part for picking up an optical image in a visible-light band; a contour-image extracting part for performing processing for extracting a contour portion from a near-infrared image acquired by the first image pickup part; and a synthesized-image generating part for adding a visible image acquired by the second image pickup part and a contour image obtained through contour extracting processing by the contour-image extracting part at a predetermined ratio to generate a synthesized image.