In this paper, an image steganography method is proposed to overcome the limitations associated with the most existing image steganography methods based on either spatial domain or transform domain. Although these methods try to increase the embedding capacity, the produced quality of the stego-images is still low and the embedding capacity is still limited by the size of cover image. To address this problem, an image steganography method based on dual tree complex wavelet transform (DT-CWT) is presented to increase the capacity and to keep the quality at its highest possible value. Also considering human visual system which is less sensitive to the edges, more secret bits can be hidden in the coefficients associated with edge pixels. Experimental results show the superiority of the proposed method in terms of capacity and image fidelity compared to the existing steganographic methods. Moreover, the proposed method is robust against universal analysis.

本文提出了一种图像隐写方法，以克服与基于空间域或变换域的大多数现有图像隐写方法相关的局限性。尽管这些方法试图增加嵌入能力，但是隐秘图像的产生质量仍然很低，并且嵌入能力仍然受到封面图像尺寸的限制。为了解决这个问题，提出了一种基于双树复数小波变换（DT-CWT）的图像隐写方法，以增加容量并将质量保持在最高可能值。同样考虑到对边缘不那么敏感的人类视觉系统，更多的秘密比特可以被隐藏在与边缘像素相关联的系数中。实验结果表明，相对于现有的隐写方法，该方法在容量和图像保真度方面具有优势。而且，所提出的方法对于通用分析是鲁棒的。