A method and an apparatus for outputting pixel data with appended data are disclosed. An imaging device in accordance with an embodiment of the present invention includes an image sensor, which outputs raw data corresponding to an external image, a memory, which stores the raw data inputted from the image sensor; an output control unit, which adds appended data to the raw data stored in the memory and outputs the added raw data, and an image signal processor, which performs image processing corresponding to at least one of filtering and interpolation of the raw data or the raw data to which the appended data are added. With the present invention, a loss of image data to be displayed can be prevented.