【作者】 杨松；

【导师】 唐正宁；

【作者基本信息】 江南大学 ， 制浆造纸工程， 2008， 硕士

【摘要】 在彩色印刷中,龟纹的出现严重影响了印刷品的质量。所以,有效抑制龟纹的出现,既改善了印刷品质量,又提高了生产效率。本论文的研究目的:通过分析龟纹产生的机理及影响因素,针对不同的龟纹类型提出不同的抑制方法。首先,本文借助鱼骨图分析的方法,得出在彩色印刷中的两种重要龟纹:半色调印刷品扫描龟纹以及分色制版龟纹。然后,通过理论分析半色调图像扫描龟纹和分色制版龟纹的产生的原因以及影响因素。其次,分别对以上两种不同的龟纹提出不同的抑制方法。最后,通过实验验证方法的可行性。本文的重点是:半色调扫描龟纹和分色制版龟纹的机理分析和实验分析。对于半色调扫描龟纹,本文将借助傅立叶变换分析半色调加网同扫描网屏之间的混淆现象。对于分色制版中的龟纹,本文将以几何学和傅立叶光谱分析为基础,使用一个光学模型来分析重叠过程中的龟纹现象。从最简单的情况入手,逐步地讨论余弦曲线栅格的重叠,方形栅格以及网点网屏的重叠。然后,以这些结果为基础,从动态学的角度来分析龟纹现象。更多还原

【Abstract】 In the color printing, the appearance of moire has affected the print quality seriously. Therefore, if we can effectively suppress the appearance of the moire, which will improve both the print quality and the production efficiency .The purpose of this article is to propose different ways for different type moires in color printing. Firstly, with the aid of the fish bones chart analysis method, this article points out two most important moires in color printing: moire in scanned halftone picture and moire in color seperation. Then, analyse the reasons and the main influencing factors of the above two moires. Next, separately proposes the different suppression method for the two different moires.Finally, confirms the the feasibility of the methods through the experiments. The key points of this article are the mechanism analysis of the moire in scanned halftone picture and the moire in color seperation and the experiments. Regarding the moire in scanned halftone picture, this article will rely on the Fourier transform to describe the confusion between halftone screen and scanning screen. About the moire in color seperation, this article depends on an optical model to analyse the superposed moire patterns in halftone screen based on the geometry and the Fourier spectral analysis. After examining the basic case of cosinusoidal grating superpositions, step by step, through the cases of square grids and dot screens. Then, based on these results, we focus on the moire phenomenon from the view of the dynamic point .更多还原