1. A character image extracting method comprising: an extracting step for obtaining a linked component composed of a plurality of mutually linking pixels from a character string region composed of a plurality of characters and extracting section elements from the character string region, the section elements each being surrounded by a circumscribing figure circumscribing to the linked component; an altering step for altering the section elements extracted in the extracting step, a new section element being formed by combining section elements at least having a mutually overlapping part among the section elements extracted in the extracting step, while remaining section elements thereof being set as new section elements without being altered; and a selecting step for selecting, from among the section elements altered in the altering step, section elements having a size greater than a predetermined reference size.