This paper proposes a self-recovery method of fragile watermarking Generally, self-recovery methods embed two types of data into the original image: check-bits for tamper detection and reference data for image recover...
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This paper proposes a self-recovery method of fragile watermarking Generally, self-recovery methods embed two types of data into the original image: check-bits for tamper detection and reference data for image recovery. Generating reference data is the primary challenge of every self-recovery method for more tamper resiliency and higher reconstruction quality. The proposed Multi-Rate Reference Embedding (MRRE) method makes unique reference data with several redundancy rates, instead of generating multiple reference data. According to the proposed methodology, the image is compressed by a sourcecoding algorithm and the compressed data is separated into ten parts. Each part is protected by a channelcoding algorithm based on pre-assigned redundancy rates. A fuzzy-based rate allocation system is used to assign the redundancy rates based on the importance of data. The generated data is packetized and randomly embedded into an image block. For tamper detection purpose, check-bits are generated by an MD5 hash function for every block. Both reference data and check-bits are embedded into three least significant bits (LSB) of the image pixels. To increase restoration efficiency, the proposed MRRE method provides ten scales of image recovery named highly-scalable self-recovery. The simulation results show an improvement in both tamper tolerability and reconstruction quality in comparison with the most recent methods.
A likelihood encoder is studied in the context of lossy source compression. The analysis of the likelihood encoder is based on a soft-covering lemma. It is demonstrated that the use of a likelihood encoder together wi...
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ISBN:
(纸本)9781479971954
A likelihood encoder is studied in the context of lossy source compression. The analysis of the likelihood encoder is based on a soft-covering lemma. It is demonstrated that the use of a likelihood encoder together with the soft-covering lemma recovers the point-to-point rate-distortion function, the rate-distortion function with side information at the decoder, and several other important inner bounds for multi-user lossy compression. The likelihood encoder also provides a way for analyzing rate-distortion based secrecy systems. Coupled with hybrid coding, new achievability results are obtained for a joint source-channel secrecy model that outperform an operationally separate source-channel coding scheme.
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