An image sensing device includes an image sensor including a first sub-pixel array and a second sub-pixel array. The first sub-pixel array includes a plurality of first pixels having a first color filter, and the second sub-pixel array includes a plurality of second pixels having a second color filter and a plurality of third pixels for phase detection. The image sensor may generate first pixel values from the first pixels, second pixel values from the second pixels and third pixel values from the third pixels. The image sensing device also includes an image processor suitable for generating a first image value corresponding to the first sub-pixel array based on the first pixel values and generating a second image value corresponding to the second sub-pixel array based on the first to third pixel values.