| 摘要 |
PROBLEM TO BE SOLVED: To easily determine a document skew angle in document image data regardless of a document format.SOLUTION: A device for document skew estimation includes: a delta value calculation part 90 that moves multiple kinds of preset base lines of different lengths along a row direction by predetermined pixels, to calculate a delta value which is a distance between an edge and each base line, the edge existing on a column orthogonal to the each base line among the outermost edges in each row and column in the document image data, and having the shortest distance to each base line, every time the base line is moved by the predetermined pixels; a delta value histogram generation part 92 for generating a histogram of the delta value for each base line; a mode detection part 94 for calculating a peak value of the histogram corresponding to the each base line; and a rotation vector calculation part 96 for calculating the skew angle of the document based on the calculated peak value. |
