| 摘要 |
PROBLEM TO BE SOLVED: To enable facilitation of extraction of retouch information retouched on a sheet and detection of alteration of existing information pre-written on the sheet.SOLUTION: Entry columns 50R are set on a sheet in advance. A two-dimensional bar code representing a first position for each entry column 50R, a second position for each word 50T and a first feature is drawn on the sheet, and the sheet is delivered to a respondent. Thereafter, an image drawn at the same position as the first position represented by the two-dimensional bar code contained in a read-out image which is read out from the sheet is extracted as retouch information. When the difference between a second feature of an image drawn at the same position as the second position represented by the two-dimensional bar code in the read-out image and a first feature corresponding to the second position represented by the two-dimensional bar code exceeds a predetermined range, the second area at the second position is extracted as an alteration area. |
