In traditional steganographic schemes, RGB three channels payloads are assigned equally in a true color image. In fact, the security of color image steganography relates not only to data-embedding algorithms but also to different payload partition. How to exploit inter-channel correlations to allocate payload for performance enhancement is still an open issue in color image steganography. In this paper, a novel channel-dependent payload partition strategy based on amplifying channel modification probabilities is proposed, so as to adaptively assign the embedding capacity among RGB channels. The modification probabilities of three corresponding pixels in RGB channels are simultaneously increased, and thus the embedding impacts could be clustered, in order to improve the empirical steganographic security against the channel co-occurrences detection. The experimental results show that the new color image steganographic schemes, incorporated with the proposed strategy, can effectively make the embedding changes concentrated mainly in textured regions, and achieve better performance on resisting the modern color image steganalysis.

The standard local binary pattern (LBP) operator shows its versatility in performing image classification-related tasks, including texture analysis, object recognition, and steganalysis. However, a conventional well-designed scheme utilizing LBP operator and histogram-based features does not have obvious advantage when compared with the well-known steganalytic scheme spatial rich model (SRM). In this paper, we propose an adapted LBP version, called threshold LBP (TLBP), to reveal the artifacts caused by data embedding. In the proposed steganalytic scheme, the TLBP operation is performed on residual images which are obtained by using a set of high-order derivative filters to capture intricate relationships among pixels. After performing TLBP operation, second order co-occurrence matrix features are formed and then processed with aggregation and non-linear mapping for boosting feature effectiveness. Experimental results show that the proposed TLBP features prevail over SRM features under various steganographic conditions.