Titre :

Adversarial Embedding in the JPEG Domain Induces Correlations Between DCT Coefficients to Remove Blocking Artifacts Generated by Additive Embedding

Auteur(s) :

Bernard, Solène [Auteur]
Bas, Patrick [Auteur]
Centre de Recherche en Informatique, Signal et Automatique de Lille - UMR 9189 [CRIStAL]
Klein, John [Auteur]
Pevny, Tomas [Auteur]

Mot(s)-clé(s) en anglais :

steganalysis
adversarial
covariance

Discipline(s) HAL :

Sciences de l'ingénieur [physics]/Traitement du signal et de l'image [eess.SP]

Résumé en anglais : [en]

This short note presents an analysis of the principle of adversarial embedding (a.k.a. adv-emb) in steganography as presented in [4]. By analyzing the covariance matrix of the stego signal of quantized JPEG coefficients ...
Lire la suite >This short note presents an analysis of the principle of adversarial embedding (a.k.a. adv-emb) in steganography as presented in [4]. By analyzing the covariance matrix of the stego signal of quantized JPEG coefficients (i.e. the signal added to the JPEG Cover image to create the Stego image), we highlight the fact that the stego signal exhibits correlations between coefficients. These weak correlations are within the same block (intra-block correlations) of between adjacent blocks (inter-block correlations). The correlation patterns are similar to the patterns of correlations analyzed on the sensor noise in the DCT domain (see [3]). However, if in [3] these correlations have been shown to favor continuities between blocks, the correlations induced by adversarial embedding are on opposite sign and they code discontinuities between blocks (see Figure 1b). An experiment consisting in generating first a cover image using J-Uniward [1] and then computing an adversarial signal using PGD [2] exhibits very similar patterns than with adversarial embedding (see figure 1c). We consequently presume that, as pictured in Figure 2, the adversarial signal is generated in order to compensate the blocking artifacts created by the embedding. This would explain the sign of the correlations. Our rationale is that the proportion β of the DCT coefficients used produce the adverse stego signal in adv-emb conveys the signal whose role is to try to remove the blocking artifacts generated by additive schemes such as J-Uniward.Lire moins >

Langue :

Anglais

Collections :

• Centre de Recherche en Informatique, Signal et Automatique de Lille (CRIStAL) - UMR 9189

Source :

Harvested from HAL