An image signal processing device is provided, which has therein a memory to store a first correction parameter to convert a specific region of display image of a display panel, a first coefficient generating section to generate a first coefficient for each pixel in a display panel based on the first correction parameter, a first correction value generating section to generate a first correction value for each pixel based on an input image signal, a first multiplier to multiply the first coefficient by the first correction value for each pixel and output a first multiplied value, and a first adder to add or subtract for each pixel the first multiplied value to or from the input image signal.