一种彩色图像的自适应灰度级数字水印算法  

A GRAY-LEVEL ADAPTIVE DIGITAL WATERMARKING ALGORITHM FOR COLOUR IMAGES

作　　者：陆萍[1] 董虎胜[1] 马小虎[2] 

机构地区：[1]苏州经贸职业技术学院信息系,江苏苏州215009 [2]苏州大学计算机科学与技术学院,江苏苏州215000

出　　处：《计算机应用与软件》2010年第5期102-104,127,共4页Computer Applications and Software

基　　金：江苏省自然科学基金项目(BK2007050)

摘　　要：提出一种基于DWT(Discrete Wavelet Transformation)与DCT(Discrete Cosine Transformation)相结合的彩色图像自适应灰度级数字水印算法。算法首先将载体图像转入YIQ空间,取Y分量经2级DWT变换后的低频子带进一步作8×8分块DCT变换,根据各子块的AC能量自适应地确定水印嵌入强度。将作为水印的灰度图像在置乱后作4×4分块DCT变换,根据获取的各子块嵌入强度实现了灰度水印的自适应嵌入。实验结果表明算法对于常见的图像处理具有较强的鲁棒性。A gray-level adaptive digital watermarking algorithm based on DWT and DCT combination for colour images is proposed.The algorithm transforms the original image into YIQ space first,when the Y component is transformed by 2-level DWT,its low-frequency sub-band is then chosen and further divided into 8×8 blocks and to be performed the DCT transformation,the intensity of watermark embedded into each sub-block is adaptively computed by its AC energy.After that,the gray image used as digital watermark is performed 4×4 blocks DCT transformation follows the chaos transformation being made.According to obtained intensity of the watermark embedded in each sub-block the adaptive embedment of gray watermark achieved.Experimental results show that the algorithm has great robustness against common image processing.

关 键 词：数字水印算法 DWT DCT Hilbert曲线变换 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]