A method and an apparatus for outputting an image by using a color filter array (CFA) sensor are provided. The method includes receiving a 4-channel combination image signal through the CFA sensor, and separating the 4-channel combination image signal into a visible image signal and a near-infrared image signal, based on a signal separation coefficient including a color coefficient that is determined to convert 4-channel color data into 3-channel color data and a weight coefficient that is determined based on a 4-channel signal configured of near-infrared image signals. The method further includes outputting the visible image signal and the near-infrared image signal.