1. An image-shooting apparatus comprising: an image-shooting portion generating an input image by shooting; and a super-resolution processing portion performing super-resolution processing on a plurality of input images obtained from the image-shooting portion to generate an output image having a resolution equal to or higher than a resolution of the input images, wherein a shutter speed at which the image-shooting portion shoots at least one of the input images is made equal to or faster than a super-resolution limit shutter speed, which is a lower-limit shutter speed that enables the super-resolution processing to make the resolution of the output image equal to or higher than the resolution of the input images.