Paweł Korus, Jarosław Białas and Andrzej Dziech
IEEE Transactions on Multimedia, Vol. 17, Issue 2, 2015
2015-tmm-jpeg-se.pdf (2 MB)
This paper deals with the design of a practical self-recovery mechanism for lossy compressed JPEG images. We extend a recently proposed model of the content reconstruction problem based on digital fountain codes to take into account the impact of emerging watermark extraction and block classification errors. In contrast to existing methods, our scheme guarantees high and stable level of reconstruction quality. Instead of introducing reconstruction artifacts, emerging watermark extraction errors penalize the achievable tampering rates. We introduce new mechanisms that allow for handling high-resolution and color images efficiently. In order to analyze the behavior of our scheme, we derive an improved model to calculate the reconstruction success probability. We introduce a new hybrid mechanism for spreading the reference information over the entire image, which allows to find a good balance between the achievable tampering rates and the computational complexity. Such an approach reduced the watermark embedding time from the order of several minutes to the order of single seconds, even on mobile devices.
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The provided supplementary materials include an additional document with full size images and more verification results, and a demonstration video which shows the operation of the developed system in practice. In particular, the supplementary document includes:
The supplementary video demonstrates: