摘要 |
To accurately extract embedded information from a document image using line spacing watermark, an image processing apparatus for extracting watermark information includes an input unit which inputs a document image as image data, an image reduction unit which generates, from the image data, reduced image data reduced in the first direction, a detection unit which scans the reduced image data in the second direction and detects the length of a blank region as line spacing information, and an extraction unit which extracts watermark information embedded in the document image based on the line spacing information.
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