Image dependent log-likelihood ratio allocation for repeat accumulate code-based decoding in data hiding channels

Anindya Sarkar; B. S. Manjunath

doi:10.1117/12.840174

27 January 2010 Image dependent log-likelihood ratio allocation for repeat accumulate code-based decoding in data hiding channels

Anindya Sarkar, B. S. Manjunath

Author Affiliations +

Proceedings Volume 7541, Media Forensics and Security II; 754113 (2010) https://doi.org/10.1117/12.840174
Event: IS&T/SPIE Electronic Imaging, 2010, San Jose, California, United States

Abstract

Error correction codes of suitable redundancy are used for ensuring perfect data recovery in noisy channels. For iterative decoding based methods, the decoder needs to be initialized with proper confidence values, called the log likelihood ratios (LLRs), for all the embedding locations. If these confidence values or LLRs are accurately initialized, the decoder converges at a lower redundancy factor, thus leading to a higher effective hiding rate. Here, we present an LLR allocation method based on the image statistics, the hiding parameters and the noisy channel characteristics. It is seen that this image-dependent LLR allocation scheme results in a higher data-rate, than using a constant LLR across all images. The data-hiding channel parameters are learned from the image histogram in the discrete cosine transform (DCT) domain using a linear regression framework. We also show how the effective data-rate can be increased by suitably increasing the erasure rate at the decoder.

Citation Download Citation

Anindya Sarkar and B. S. Manjunath "Image dependent log-likelihood ratio allocation for repeat accumulate code-based decoding in data hiding channels", Proc. SPIE 7541, Media Forensics and Security II, 754113 (27 January 2010); https://doi.org/10.1117/12.840174

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available