The impact of channel coding on the performance of spatial watermarking for copyright protection

Hernández, Juan Ramón Hernández; Pérez-González, Fernando; Rodriguez, J.M.

doi:10.1109/icassp.1998.678150

Cited by 30 publications

(20 citation statements)

References 6 publications

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“…The bit string is then encrypted using a key-dependent primitive (based on the secret key k) and mapped from {0; 1} to {−1; 1}, resulting into a codeword c = (c 1 ; : : : ; c K ) T , with c i ∈ {−1; 1}, i = 1; : : : ; K, followed by a spreading over a rectangular or square block of size t 1 × t 2 with some density The message is encoded using ECC with soft decoding [23] such as Turbo codes [3] or the Low Density Parity Check Codes (LDPC) [20], that belongs to the iterative coding codes, and which we tested at rates r ecc = 1 2 or r ecc = 1 3 ; the lower is the rate, the more robust to distortions is the codeword. Such ECC encoding achieves signiÿcantly superior performance than binary modulation or any other codes based on hard decoding, like the BoseChaudhuri-Hocquenghem (BCH) cyclic codes which are often used in the watermarking community.…”

Section: Message Encodingmentioning

confidence: 99%

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Secure hybrid robust watermarking resistant against tampering and copy attack

2003

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Digital watermarking appears today as an e cient mean of securing multimedia documents. Several application scenarios in the security of digital watermarking have been pointed out, each of them with di erent requirements. The three main identiÿed scenarios are: copyright protection, i.e. protecting ownership and usage rights; tamper prooÿng, aiming at detecting malicious modiÿcations; and authentication, the purpose of which is to check the authenticity of the originator of a document. While robust watermarks, which survive to any change or alteration of the protected documents, are typically used for copyright protection, tamper prooÿng and authentication generally require fragile or semi-fragile watermarks in order to detect modiÿed or faked documents. Further, most of robust watermarking schemes are vulnerable to the so-called copy attack, where a watermark can be copied from one document to another by any unauthorized person, making these schemes ine cient in all authentication applications. In this paper, we propose a hybrid watermarking method joining a robust and a fragile or semi-fragile watermark, and thus combining copyright protection and tamper prooÿng. As a result this approach is at the same time resistant against copy attack. In addition, the fragile information is inserted in a way which preserves robustness and reliability of the robust part. The numerous tests and the results obtained according to the Stirmark benchmark demonstrate the superior performance of the proposed approach. ?

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Section: Message Encodingmentioning

confidence: 99%

“…based on the central limit theorem (CLT), since most researchers assume that the observed vector r can be accurately approximated as the output of an additive Gaussian channel noise [23,30] for a large sample space. We use the Bahl-Cocke-Jelinek-Raviv (BCJR) decoder [3] for the Turbo codes.…”

Section: Robust Message Decodingmentioning

confidence: 99%

Secure hybrid robust watermarking resistant against tampering and copy attack

2003

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“…Error correction techniques of channel coding such as the BCH (Bose-Chaudhuri-Hockquenghem) codes can be used to improve the robustness of spatial-domain watermarks [2]. A number of the related coding methods were studied in the late 1990's [3].…”

Section: Introductionmentioning

confidence: 99%

Enhancement of Error-Correction Coding of Spatial Watermarks for JPEG Compression

Kimoto

2012

2012 Eighth International Conference on Signal Image Technology and Internet Based Systems

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This paper demonstrates how channel coding can improve the robustness of spatial image watermarks against JPEG DCT-based compression. Two error-correction coding (ECC) schemes are used here. One scheme, referred to as the vertical ECC (VECC), is to encode information bits in pixel levels by error-correction coding where the Gray code is used to improve the performance. The other scheme, referred to as the horizontal ECC (HECC), is to encode information bits in an image plane by error-correction coding. VECC is also used to encode the code bits of HECC in pixels. Simple single-error-correcting block codes are used in VECC and HECC. Several experiments of these schemes were conducted on test images. The result demonstrates that the errorcorrecting performance of HECC depends on that of VECC, and accordingly, HECC enhances the capability of VECC. Consequently, HECC with appropriate codes can achieve stronger robustness to JPEG-caused distortions than nonchannel-coding watermarking schemes.

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“…The PS method reduces effects of signal distortions on the embedded watermark by averaging pixel values, which is a kind of low pass filtering. On the other hand, error correcting techniques in channel coding such as the BoseChaudhuri-Hockquenghem (BCH) codes [4] can be used to improve robustness of spatial-domain watermarks [5]. A number of the related coding methods were studied in the late 1990's [2].…”

Section: Introductionmentioning

confidence: 99%

Spatial Image Watermarking by Error-Correction Coding in Gray Codes

Kimoto¹

2013

JSIP

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In this paper, error-correction coding (ECC) in Gray codes is considered and its performance in the protecting of spatial image watermarks against lossy data compression is demonstrated. For this purpose, the differences between bit patterns of two Gray codewords are analyzed in detail. On the basis of the properties, a method for encoding watermark bits in the Gray codewords that represent signal levels by a single-error-correcting (SEC) code is developed, which is referred to as the Gray-ECC method in this paper. The two codewords of the SEC code corresponding to respective watermark bits are determined so as to minimize the expected amount of distortion caused by the watermark embedding. The stochastic analyses show that an error-correcting capacity of the Gray-ECC method is superior to that of the ECC in natural binary codes for changes in signal codewords. Experiments of the Gray-ECC method were conducted on 8-bit monochrome images to evaluate both the features of watermarked images and the performance of robustness for image distortion resulting from the JPEG DCT-baseline coding scheme. The results demonstrate that, compared with a conventional averaging-based method, the Gray-ECC method yields watermarked images with less amount of signal distortion and also makes the watermark comparably robust for lossy data compression.

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The impact of channel coding on the performance of spatial watermarking for copyright protection

Cited by 30 publications

References 6 publications

Secure hybrid robust watermarking resistant against tampering and copy attack

Secure hybrid robust watermarking resistant against tampering and copy attack

Enhancement of Error-Correction Coding of Spatial Watermarks for JPEG Compression

Spatial Image Watermarking by Error-Correction Coding in Gray Codes

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