Enlarging or reducing an image on a display screen

A method, and associated apparatus and system and program product, for enlarging or reducing an image. The image is displayed on a display screen. A pointing operation is detected. The pointing operation points to, with a single-touch gesture using pointing means on the display screen, a first figure indicative of a range of the image to be enlarged or reduced and a second figure indicative of a size of the enlarged or reduced range. In response to the detection of the pointing operation, an enlarged or reduced image is displayed after the enlarged or reduced image is obtained by enlarging or reducing the image at an enlargement or reduction ratio determined based on the first figure and the second figure.