Image signal processor and mobile device including image signal processor

The present invention relates to an image signal processor. The image sensor processor of the present invention is configured to output a Bayer image signal by converting into a normal image signal. The image signal processor comprises: a memory to store a table including reference brightness values and variation values of the Bayer image signal; a shot noise reduction unit which calculates a reference brightness value of the Bayer image signal, selects a variation value in the table, performs shot noise reduction on the Bayer image signal based on the selected variation value; and an interpolation unit which performs interpolation based on the shot noise reduced Bayer image signal.