Abstract: A 2-dimensional code region extraction device (FIG. 2) includes: a scan unit 11 for scanning image data containing a 2-dimensional code vertically and horizontally; a blank space detection unit 12 for detecting a blank space portion by determining the white/black gradation of scanned pixels; a non-blank space information calculation unit 13 for calculating the length and central coordinates of a non-blank space portion that exists between the detected blank space portions; a comparison unit 14 for comparing the lengths and central coordinates of the non-blank space portions that exist in the vertical and horizontal directions, respectively so as to determine the presence of a 2-dimensional code, and detecting a 2-dimensional code candidate region; and a rank determination unit 15 for comparing a plurality of 2-dimensional code candidate regions that are detected and ranking them.