为了提高隐写算法的安全性能, 提出了一种利用无方向性滤波器设计的空域自适应隐写算法。首先, 利用无方向性滤波器对载体图像进行滤波计算, 获得图像中难于被建模检测分析的复杂区域, 然后利用高斯低通滤波器对复杂区域进行平滑处理, 增加嵌入信息区域相邻像素间的相关性, 进而得到损失函数, 最后按照损失函数通过校验格编码完成信息嵌入。抵抗富模型隐写分析实验表明: 当信息嵌入率较小时, 该算法的抗检测性能与S-UNIWARD算法相近; 当信息嵌入率较大时, 该算法优于S-UNIWARD算法。

Aiming at improving steganography security, a novel adaptive steganographic algorithm designed by non-directional filter is proposed. Firstly, the complex regions are determined by a non-directional filter in images. Secondly, a Gaussian low-pass filter is used to enhance the coherence of different pixels in those regions and then the cost function is established. Finally, according to the cost function, messages are embeded by syndrome trellis codes. Experimental results illustrate that steganographic algorithm achieves a better performance on resisting the state-of-the-art steganalysis over prior work than that of S-UNIWARD under the condition of large embedding rates and a similar performance under the condition of small embedding rates.