An image resolution converting device for converting an original image into an image of a predetermined resolution includes: a pixel value storage section for storing the pixel values of the pixels included in the original image; a region determining section for successively determining regions, disposed newly generated pixels in accordance with a raster-scanned disposition order of the newly generated pixels; a pixel value read-out controlling section for generating output-control signals serving for outputting the pixel values of the pixels; and an interpolation-calculating section for calculating interpolations of pixel values of the newly generated pixels in accordance with the interpolated pixel values. It is possible to provide an image resolution converting device which can select the pixel groups of the original image, used for generating the new pixels after the resolution conversion while realizing small-size circuits used in the device.