文中提出了一種基于離散小波變換和混沌加密的數(shù)字水印新算法,采用二維混沌變換對水印圖像加密 對載體圖像進行多分辨離散小波變換,應用小波系數(shù)判斷載體圖像的紋理復雜程度后,依據(jù)人眼的視覺系統(tǒng)(HVS)特性,將水印信號嵌入到圖像的低頻部分,對圖像的不
同分解層分別選取不同的紋理閾值和水印嵌入強度,將數(shù)字水印嵌入到相同分辨層的原始圖像中,提高了水印算法的魯棒性。在檢測和提取水印時,通過水印相似度(NC)和峰值信噪比( PNSR)評價水印質量,實驗結果表明提出的算法可以抵抗剪裁、JPEG壓縮、濾波等幾何攻擊,算法簡單,計算復雜度小,兼顧了水印的不可見性和魯棒性。
標簽：
HVS
離散小
波變換
加密
上傳時間：
2016-10-24
上傳用戶：Andy123456
The "GEE! It s Simple" package illustrates Gaussian elimination with partial pivoting, which produces a factorization of P*A into the product L*U where P is a permutation matrix, and L and U are lower and upper triangular, respectively.
The functions in this package are accurate, but they are far slower than their MATLAB equivalents (x=A\b, [L,U,p]=lu(A), and so on). They are presented here merely to illustrate and educate. "Real" production code should use backslash and lu, not this package.
標簽：
illustrates
elimination
Gaussian
pivoting
上傳時間：
2016-11-09
上傳用戶：wang5829
