Provided are an image composition apparatus for composing color images with black-and-white images including infrared components, and an image composition method thereof The image composition method includes generating a first image signal with color information and a second image signal including infrared components without color information, dividing the first image signal into a brightness signal and a color signal, composing the brightness signal of the first image signal with a brightness signal of the second image signal to generate a composed brightness signal, and composing the composed brightness signal with the color signal of the first image signal to generate a color image.