CMYK与RGB颜色空间数字水印 在印刷品中的应用比较

为提高水印抗印刷/扫描攻击的鲁棒性,比较了在CMYK与RGB颜色空间嵌入的水印经印刷/扫描后提取的效果.采用离散小波变换域傅里叶全息数字水印算法生成水印图像,经印刷/扫描后,可以提取到水印;然而,由于印刷/扫描过程中颜色空间的转换,使得原本嵌入某一颜色通道的水印转移到其他通道,降低了单通道提取的水印质量;且相对于RGB颜色空间,在CMYK颜色空间嵌入水印生成的水印图像经历印刷/扫描后提取到的水印质量普遍较高,说明CMYK→RGB→CMYK颜色空间的转换相对于RGB→CMYK→RGB颜色空间的转换,对水印图像的改变较小.为减小印刷/扫描攻击的影响,考虑下一步研究工作主要集中在CMYK颜色空间嵌入水印.

The Application of Digital Watermarking Technology for Printings in CMYK and RGB Color Space

In order to study the effect of the opening hole on mechanical properties of L shaped short pier shear wall, applies ANSYS finite element software to investigate the mechanical properties of short pier shear wall of different opening rates under the unchanged cross-sectional dimensions and reinforcement rates of the wall, and analyzes the bearing capacity and yield displacement. The simulated results show that the bearing capacity decreases with the openings rate increment and the bottom of the web as well as the opening position of the short pier shear wall are the weakest. Opening holes will reduce the mechanical properties of short pier shear walls under monotonic loading, and the opening diameter on short pier shear walls should not be too large.