1. An image reading method of reading a mixed image and a decimated image from an input image which is captured, the mixed image and the decimated image being used for super-resolution, said image reading method comprising: determining a reading position of a reading pixel of the mixed image and the decimated image for each input image, so that the reading position moves differently for each input image; reading the mixed image from the input image according to the determined reading position, by mixing signals of adjacent pixels; and reading the decimated image from the input image according to the determined reading position, by selecting signals of spatially-separated pixels.