1. An image processor that corrects image signals corresponding to sub-pixels which form one pixel, comprising: a shift amount storage section that stores shift amounts of display positions of display sub-pixels corresponding to the sub-pixels which form a display pixel with respect to a predetermined reference position within a display image; and an image signal correcting section that corrects image signals corresponding to sub-pixels, which form each pixel of an input image, on the basis of the shift amounts stored in the shift amount storage section, wherein the image signal correcting section corrects image signals in which dummy image signals corresponding to dummy sub-pixels, which are provided outside sub-pixels in an endmost portion of the input image, are added to input image signals of the sub-pixels.