摘要:
将秘密信息扩频嵌入载体图像的每个8×8维离散余弦变换(DCT)系数矩阵的一个元素内,并根据嵌入位置的不同对隐秘图像作基于DCT特性的相应变换,可提高扩频算法的隐蔽性。基于DCT特性的扩频算法不需要减少嵌入强度亦可提高隐秘图像的峰值信噪比值,可避免因嵌入强度减少导致秘密信息提取误差变大的问题。为克服取整误差的影响和提高秘密信息提取的准确率,根据推导所得的提取误差的概率密度函数,提出容错提取算法。仿真结果验证了该算法的可行性和有效性。
关键词:
图像隐藏,
离散余弦变换特性,
提取误差,
容错提取
Abstract:
The secret information is embedded in one of elements of every 8×8 Discrete Cosine Transform(DCT) coefficient matrixes of cover image, and based on DCT characteristic the stego-image is correspondingly changed according to different embedded locations, which can improve imperceptibility of Spread Spectrum(SS) algorithm. Simulation results indicate that the SS algorithm based on DCT characteristic can improve Peak Signal to Noise Ratio(PSNR) of stego-image not by reduction of embedment strength, thus avoids the problem that reduction of embedment strength enlarges retrieval errors. In order to effectively overcome the adverse effect of round error and raise accuracy rating, a fault-tolerant retrieval algorithm is proposed according to the probability density function of retrieval errors. Simulation results verify the feasibility and validity of the algorithm.
Key words:
image hiding,
Discrete Cosine Transform(DCT) characteristic,
retrieval errors,
fault-tolerant retrieval
中图分类号:
陈伟超, 敖珺, 马春波. 基于DCT特性的图像隐藏稳健扩频算法[J]. 计算机工程, 2011, 37(10): 117-119.
CHEN Wei-Chao, AO Jun, MA Chun-Bei. Image Hiding Algorithm of Robust Spread Spectrum Based on DCT Characteristic[J]. Computer Engineering, 2011, 37(10): 117-119.