System and method for data hiding in compressed fingerprint images
AssigneeInternational Business Machines Corporation
InventorsRudolf Maarten Bolle, Jonathan Hudson Connell, Nalini Kanta Ratha
Life of this patent
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Abstract
A method to hide small messages in a wavelet compressed fingerprint image is presented. The method is characterized by random placement of the message bits in the compressed and quantized indices. The compressed image can be decompressed by any certified decompressor without any visible difference. However, the decoder aware of the decompression can only retrieve the hidden message in the image and additionally decompress the image without any error in pixel values.
Claims18
A computer system for hiding an information sequence in a compressed image comprising:
- an image compressor that spatially compresses an image to create a spatially compressed image with a plurality of frequency components, each with a respective spatial frequency and a respective amplitude;
- a candidate selector that selects a selected set of a plurality of the frequency components, the selected set having the frequency components with high spatial frequencies and large amplitudes;
- a data site selector that uses a random process to randomly select from the selected set to create a site set;
- and
- a site modifier that partitions the information sequence into one or more portions and uses one or more of the portions to modify one of the amplitudes of one of the frequency components in the site set.
A computer system for extracting a hidden information sequence from a compressed image comprising:
- an image decompressor that partially decompresses the image to create a plurality of frequency components, each with a respective spatial frequency and a respective amplitude;
- a candidate selector that selects a selected set of a plurality of the frequency components, the selected set having the frequency components with high spatial frequencies and large amplitudes;
- a data site selector that uses a random process to randomly select from the selected set to create a site set;
- and
- a message extractor that uses one of the amplitudes of one of the frequency components in the site set to extract one or more portions of the information sequence.
Dependencies are inferred from the claim text.