文本文档水印质心检测方法的改进

对Brassil等的文本水印质心检测方法作了改进，通过模拟扩展初始文本行，综合应用再生文本行轮廓和初始文本行轮廓信息构造了一个再生模拟文本行质心序列，证明了该序列依概率收敛于初始文本行质心。实验结果表明改进后的检测方法在处理含有短行的文本文档水印时较之与Brassil方法，误检概率可减少一半，因此用行移编码嵌入水印时可不受文本行长度限制，提高了文档水印容量。

Improvement on centroid detection method for text document watermarking

An improvement on centroid detection method invented by Brassil et al was presented.The improved method constructs a centroid series which were convergent in probability to centroid of initial text line using both initial profile and reproduced profile of text line.Experimental result shows that the new approach may half down the probability of detection error in the case of short text lines in comparison with the Brassil' method.The conclusion suggests that line-shift coding would not be subject to text line length again,either long lines or short lines are all used to embed watermark,and the watermark capacity is increased.