An information processing apparatus capable of storing more data to a remaining region of a storage portion excluding a frame buffer region while displaying an image by an image display portion, is provided. When free space of a system storage portion has become below a predetermined value, a reduction in number of gray scales of the image results in a reduction in a data amount of image data stored in a display data storage region and a reduction in capacity of the display data storage region. This makes it possible to reduce the data amount of image data and increase the free space of the system storage portion while keeping the size of the image displayed by an image display portion.