为了确定自适应隐写中载体图像复杂区域, 提高像素间相关性, 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。利用无方向性滤波器对载体图像进行滤波计算, 获得图像中难以被建模检测分析的复杂区域, 再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。实验结果表明, 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。

In order to obtain the complex regions of cover image in adaptive steganography and improve the coherence between pixels, a novel adaptive steganography algorithm based on non-directional filter is proposed. The complex regions, which are difficult to be modeled and detected, are obtained by filter calculation on images through using a non-directional filter. The Gaussian low-pass filter is used for smoothing the complex regions, and enhance the coherence of different pixels in those regions and the cost function is established. Finally, according to the cost function, the messages are embedded by syndrome trellis codes. Experimental results demonstrate that the performance of anti-detection by the proposed algorithm is similar as that of the S-UNIWARD algorithm when the information embedding rate is small, and the proposed algorithm is better than the S-UNIWARD algorithm when the information embedding rate is large.