1. An endoscope apparatus comprising: an illumination unit configured to selectively provide a white light and additional lights having respective different wavelength bands; a sensing unit configured to receive light reflected from a body cavity, and generate a color image captured by the white light, and images of the respective different wavelength bands that are captured by the additional lights, the sensing unit comprising a red sub-pixel, a green sub-pixel, and a blue sub-pixel; and an image processing unit configured to generate a blue narrow band image by converting image components captured by the blue sub-pixel from the respective images to blue binary images, respectively, and performing an AND operation on the blue binary images, generate a green narrow band image by converting image components captured by the green sub-pixel from the respective images to green binary images, respectively, and performing an AND operation on the green binary images, generate an IR narrow band image by converting image components captured by the red sub-pixel from the respective images to red binary images, respectively, and performing an AND operation on the red binary images, and generate a synthesized image by combining at least two of the blue, green, and IR narrow band images.