摘要
在當(dāng)今的視頻傳輸與廣播網(wǎng)絡(luò)中，版權(quán)的保護(hù)問題已經(jīng)變得越來越緊迫。這是因?yàn)橐曨l拷貝的出現(xiàn)并沒有降低原始視頻文件的品質(zhì)。一種保護(hù)版權(quán)的方法是在視頻序列中嵌入一段數(shù)字密碼，這段數(shù)字密碼的學(xué)術(shù)名稱叫做水印。
因此，這篇課題的目的就是研究低復(fù)雜度的壓縮域H.264視頻水印算法。視頻編碼標(biāo)準(zhǔn)決定了H.264/MPEG-4 AVC的壓縮標(biāo)準(zhǔn)。這種算法充分使用了H.264壓縮標(biāo)準(zhǔn)了明確性，原始視頻的水印也是被隨機(jī)嵌入的。這些都建立在水印算法安全的基礎(chǔ)上。
在這種基于壓縮域的H.264視頻水印算法方案中，水印可以在沒有原始視頻序列存在的條件下被檢測出來。水印可以在所選的編碼器修正系數(shù) 的幫助下提取出來。
被提議的視頻水印方案
導(dǎo)言
在這項(xiàng)方案中，使用的是被提議的基于壓縮域的H.264視頻水印算法，它工作在I幀的宏塊層上。在這一層上，一個(gè)宏塊中包含視頻幀的一個(gè)16×16的采樣區(qū)域。從這個(gè)包含于一個(gè)宏塊上的16×16采樣區(qū)域中，我們?nèi)〕鲆粋€(gè)8×8的分塊。從這個(gè)8×8的分塊中，我們進(jìn)一步提取一個(gè)4×4的分塊，用 , , 和 表示一個(gè)宏塊中的4種不同的4×4分塊。這個(gè)4×4分塊將幫助我們在FDCT（快速離散余弦變換）之前構(gòu)建4×4 DCT系數(shù)的輸入分塊。
ABSTRACT
In today's video delivery and broadcast networks, issues of copyright protection have become more urgent than in analog times. This is simply due to copying of digital video does not result in the decrease in quality that occurs when analog video is copied. One of the methods of copyright protection is to embed a digital code into the video sequence. The digital code is termed as watermark..
Therefore, the objective of this project is to propose a digital video watermarking algorithm for H.264 in the compressed, domain whose complexity is low. The video coding standard decided to use was the H.264/MPEG4 AVC compression standard. The proposed algorithm exploits the specific characteristics of the compression standard H.264. The watermark to be embedded into the original video is randomly localized. It is on this foundation that our proposed video watermarking algorithm bases its secureness.
In this proposed video watermarking algorithm for H.264 in the compressed domain, the watermark can be detected without the presence of the original video sequence. The watermark is blindly extracted by the help of the selected modified coefficient, at the decoder.