| 摘要 |
PROBLEM TO BE SOLVED: To perform quick detection of a bar code area by shortening a processing time and to perform highly precise bar code detection by eliminating an image noise in printing or the like other than that of the bar code. SOLUTION: The maximum extremum value is detected from a projected picture element density distribution (k) for projecting the picture element density in a horizontal direction to two-dimensional picture data and a range based on a minimum value or the least value adjacent to this maximum extremum is judged to be a vertical direction range of a bar code area. Then, in the height direction ranges (n) and (p) of the judged bar code area, the picture element density is projected in the vertical direction and a projected picture element density distribution (q) is obtained, the extremum is detected from this projection and part of a continued extremum more than a specified number with space between adjacent extremums is within a specified ratio range is detected. Then, a central coordinate of extremums of the first and the last detected parts becomes a central coordinate in the width direction of a bar at both ends of a bar code (g) and thus the width direction range of the bar code area is judged and the bar code area is detected by this width direction range and the height direction range. |
