Question

哪位英语高手能帮我翻译下面这段英文，不要机器翻译的，谢！！给分！！

Note that for better efficiency, lossless data embedding is per- formed on the image as a whole rather than on a block by block basis. Also observe that encryption of the payload and the com- pressed bit stream readily yields an implementation in which the recovery of the original image and embedded data is dependent on a cryptographic key.
The authentication watermarking step (b), uses the hierar- chical image authentication scheme [18] on the image obtained after the pre-embedding step. The hierarchical block-based wa- termarking technique inserts and extracts a watermark in a mul- tilevel hierarchy. The (nonoverlapping) blocks of the pre-em- bedded image shown in Fig. 4 constitute the lowest level of the hierarchy. Successive levels of the hierarchy are formed by com- bining distinct groups of blocks at a preceding level of the hi- erarchy. In general, the number of blocks from a lower level of the hierarchy that are combined to form a block at the next level of the hierarchy may be arbitrarily chosen, however, in order to keep the notation and the description simpler, we assume for the rest of this paper that the region of 2 2 blocks at a given level of the hierarchy are combined to create a block at the next level of the hierarchy, giving us a quad-tree for the hierarchy as shown in Fig. 6.
For each block at each level of the multilevel hierarchy, a dig- ital signature or message authentication code (MAC [2]) is com- puted for the data (in the pre-embedded image) within the block. A standard digital signature algorithm operates on the concate- nation of all binary digits representing the pixel values in the block (blocks at higher level of the hierarchy use all the image bits within the corresponding region). These signature are then placed in the part of the image data locations corresponding to LSBs of shaded regions in Fig. 4. In order to incorporate lo- calization capability, the distribution of the signature informa- tion bits also follows the quad-tree hierarchy as illustrated in
Fig. 6: the LSBs for the shaded region within each block con- tain all of the signature for the block at the lowest level of the hierarchy in which it is located, 1/4 of the signature bits for the second level of the hierarchy, 1/16 of the signature bits for the third level of the hierarchy, and so on. This packetization of signatures ensures that the signature of each block is contained within the part of image bits for the block. The hierarchical nature of the scheme provides security against vector-quantiza- tion attacks [21] and good tamper localization accuracy. Addi- tional details on the hierarchical authentication method may be found in [18]

Answer 1

自己理解吧 （注意,为了更好的效率、无损嵌入是建立在每—图像作为一个整体,而不是在一个街区由块的基础。也观察到加密的有效载荷及com -按码流容易实现的收益中恢复原来的形象和嵌入式数据依赖于一个密钥。
认证水印一步(b),采用hierar - chical认证方案[d]形象的图像pre-embedding后。这个层次块佤族- termarking技术提取水印嵌入和在为tilevel -层次。(nonoverlapping)的pre-em -岩体的图像显示在图4构成的最低层次的层次。连续的水平层次是由com - bining截然不同的组块在前一等级的hi - erarchy。总的来说,这个数目的街区由低级的层级,结合起来,形成一个街区的下一阶段的人可以任意选择的层次,然而,为了保持简单的符号和描述,我们假设剩下的文章,该地区的2个2块在一个特定的等级层次的结合起来,创造一个街区的下一阶段的层次,给我们一个四叉树的层次如图。6。
在每一级为每个街区的多层次的层级,挖掘签名或信息至关重要—认证码(MAC[2])数据通讯-内(预理图像)在街区。一个标准的数字签名算法运行的concate -国家所有的二进制数字代表像素值块(块更高级别的层级上使用所有的图像碎片在相应的区域)。这些签名然后放置在部分的图像数据的地点对应的LSBs阴影区域,如图4。为了将洛- calization能力、分布的签名信息-兴比特也遵循四叉树的层次
图六:LSBs阴影区域内的每一个街区的欺诈-全部的签名的街区层次的最低水平,它位于,1 / 4的签名位第二级的层级上的签名,16位的第三个层次,等等。这packetization签字的签名确保每个区块内的部分图像位块。这个层次性质的计划提供的安全防范vector-quantiza -兴攻击(21)和良好的篡改定位精度。传统的具体细节,另—认证方法可能会发现分层[d]）

Answer 2

看了..是一编关于保存数据的文章