A demosaic operation circuit includes a white pixel value estimation circuit suitable for acquiring an RGB channel average value and a directional gradient value of a white pixel for each direction using source pixel data provided from a pixel array, and estimating a white pixel value based on the RGB channel average value and the directional gradient value of the white pixel; a fine adjustment circuit suitable for finely adjusting an estimated white pixel value by removing noise through a different filter based on weight values which are differently allocated according to a gradient of a center pixel and a neighboring white pixel; a chroma estimation circuit suitable for estimating a chroma by calculating a chroma array based on the source pixel data and an adjusted white pixel value; and a color correction circuit suitable for correcting a color based on a finely adjusted white pixel value and the chroma.