摘要 |
When creating a marker, an encryption apparatus extracts each pixel value in a region and allows a storing unit to save, as restoration information, the high-order bits of each extracted pixel value. Then, the encryption apparatus creates a marker by changing the high-order bits of the pixel value in a region in which the marker is created and embeds encrypted information in an encrypted region specified by the marker. When decoding the encrypted information, a decoding apparatus detects the marker from a digital image, decodes the encrypted information in the encrypted region specified by the marker, and overwrites bits contained in the restoration information with the high-order bits of the pixel value of the marker.
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