Abstract: A device for processing an image signal that can improve an image quality of a zoom image in which based on an input image signal, an image-signal-processing section produces an output image signal to display the zoom image with an expansion rate of an image being changed consecutively around an arbitrary center point specified by the user. Each pixel data of the output image signal is calculated by using coefficient data produced by a coefficient production circuit that produces the coefficient data based on not only phase information of each pixel but also resolution adjustment information and noise suppression degree adjustment information that the image quality adjustment information generation circuit generates based on the expansion rate of the image, a change rate (K) of the expansion rate of the image, and characteristics information of the image.