An image sensor includes a Bayer pattern-type pixel array including a plurality of Bayer pattern-type extended blocks each having first to fourth pixel blocks, each of the first to fourth pixel blocks including first to fourth pixels, the first and fourth pixels of the first and fourth pixel blocks being configured to sense green light, the first and fourth pixels of the second and third pixel blocks being configured to sense red light and blue light, respectively, and the second and third pixels of the first to fourth pixel blocks being configured to sense white light, and a signal processing unit merging Bayer pattern color information generated from the first and fourth pixels of the first to fourth pixel blocks, and the Bayer pattern illuminance information generated from the second and third pixels of the first to fourth pixel blocks.