1. An imaging apparatus comprising: an optical element that disperses a received light into a first light which includes wavelength components in a visible light region and a second light, different from the first light, which includes wavelength components in a near-infrared light region; a color image pickup device that receives the first light from the optical element; a monochrome image pickup device that receives the second light from the optical element; an image acquisition unit that obtains color image data from the color image pickup device and monochrome image data from the monochrome image pickup device; a color information extraction unit that extracts color information from color image data from the image acquisition unit; a luminance information extraction unit that extracts luminance information from monochrome image data from the image acquisition unit; and a synthesis unit that synthesizes the extracted color information and the extracted luminance information to generate composite image data, wherein the image acquisition unit removes from the color image data from the color image pickup device wavelength components in the near-infrared light region prior to sending the color image data to the color information extraction unit, and wherein the image acquisition unit removes from the monochrome image data from the monochrome image pickup device wavelength components in the visible light region prior to sending the monochrome image data to the luminance information extraction unit.