计算图 meaning in English
calculating chart
calculation chart
nomogram
pattern of calculation
scaling system
Examples
- In this article , a algorithm ccn ( calculate crossing number ) is put forward to study the crossing number . it is a very important development in graph planarity issue after planarity - determinant algorithm and embedding algorithm
本文首次给出了较好的计算图的交叉数算法ccn ( calculatecrossingnumber ) ，这是继图平面性判定算法，二连通图的平面嵌入算法之后在图的平面性问题上的一个最重要的进展。 - But , though considerable process has been made in the last ten years , digital watermarking is still in its infancy , and much interesting work remains to be done this thesis addresses some problems in the gray - scale image digital watermarking that are summarized below : 1 ) whereas the basic theory of digital watermarking is still very poor , a digital watermarking mathematic model based on imperceptibility and robustness is presented by analysising the characteristic of digital watermarking ; 2 ) based on the model constructed above , by defining the measures of capacity and robustness of digital watermarking , an objective method for evaluating the digital watermarking is introduced and used to analysis some algorithms ; 3 ) whereas geometric distortion always influences the restoration of watermark , we advocate to enhance the robustness against geometric distortion by restoring the image which has been distorted by geometric transformation , and a method is designed for estimating the parameters of geometric transformation ; 4 ) based on the conclusion discussed above , and combined with the masking effects of hvs , a novel public meaningful gray - scale image digital watermarking is designed by analysising the characteristics of image gray - scale interpolation and haar wavelet transformation . the experimental results show that the method is indeed powerful ; 5 ) whereas many image digital watermarking schemes , which embed watermark by modifying the values of pixels in spatial domain and transformed domain , are confronted with the conflict between the imperceptibility and robustness , we advocated to use some stable digital characteristics of host image as watermark and a algorithm based on hermite matrix is designed
本文重点对灰度图象数字水印技术进行研究，主要工作如下： 1 )鉴于目前数字水印的理论研究比较薄弱的现状，本文通过分析数字水印的特点，建立了一个数字水印的数学模型，为进一步研究数字水印打下了基础； 2 )根据以上建立的模型，通过引入容量和稳健度的概念为数字水印提供了一个客观评价方法，并对一些数字水印算法进行了分析； 3 )为增强数字水印抵抗几何攻击的能力，研究了受几何攻击的图象的复原问题，并给出了一个计算图象几何变换参数的方法； 4 )通过分析图象灰度插值算法和haar小波变换的特点，结合hvs的掩蔽效应，设计了一个公开的有意义数字水印算法，实验结果表明本算法具有较强的稳健性； 5 )目前许多水印算法都是通过在空域或频域修改象素值的方法嵌入水印的，这种方法面临着透明性和稳健性的矛盾，为解决这个矛盾，本文提出以图象的某些稳定的数字特征为水印的观点，并结合hermite矩阵的特点设计了相应的水印算法，实验结果表明该算法具有较好的稳健性。