Infrared light emitted by a fluorescent material is weak. When an infrared image obtained by this fluorescent material is superposed and displayed on a visible-light image, the infrared image is made clear. A signal of an IR pixel having selective sensitivity to infrared light is subtracted from RGB pixel signals , , and of a solid-state image sensor by adders (20), and signals R0, G0, and B0 that correspond to the R, G, and B components of incident light within , , and are separated and extracted. is multiplied by each of the gains κR, κG, and κB to enhance the IR component by multipliers (22), and each is synthesized with R0, G0, and B0 by adders (24). κR, κG, and κB are set so that the infrared image displayed on the visible-light image by the synthesized IR component is enhanced and displayed in a hue that can be distinguished from the color white or another visible-light image.