In order to study the preferred skin color for printing images,two CMYK images from ISO 400 and one from iStock,including five skin color images of East Asian females was selected in this study.The images were adjuste...In order to study the preferred skin color for printing images,two CMYK images from ISO 400 and one from iStock,including five skin color images of East Asian females was selected in this study.The images were adjusted with the CMYK printing ink volume variation of the single,double and triple channels in the given 280%total ink limit conditions.A larger number of color vision normal observers were organized to carry out the color preference evaluation experiment,and the selected preferred skin colors were analyzed.The distribution range of the chromaticity values for skin color images were obtained and the results indicated that there are three regions for printing skin color preferences,and the observers have a memory preference for brighter,fairer skin colors in young female and a reddish skin colors in girl,which can provide the guidance for color adjustment of printed skin color images.展开更多
In the printing industry,the common method of coloring relies on inks,which contains amounts of chemical agents,causing environment pollution.However,structural color achieves coloration through the refraction and dif...In the printing industry,the common method of coloring relies on inks,which contains amounts of chemical agents,causing environment pollution.However,structural color achieves coloration through the refraction and diffraction of light by periodic structure,offering eco-friendly and fade-resistant advantages,as well as colorful.In this study,screen printing was used to create patterned mask on paper substrates.Then,coated SiO_(2)microspheres on the mask to create structural color patterns with angle-dependent color characteristics.The patterns showed color changes from rose-red to orange to green by changing the viewing angle.By changing the color grayscale,the absorption of stray light by the substrate was enhanced,thereby the brightness and saturation of the structural color improved too.This method is simple,cost-effective,and environmentally friendly,and it has highly promising for the application in printing and anti-counterfeiting.展开更多
彩色点画是一种从视觉上由大量小像素点构建图像的艺术技术,像素个数的多少直接影响着构图的成本。其优化选点构图方法为实现低成本打印提供了一个重要的方式。目前,点画生成存在着多通道采样点难以均匀分布,颜色层次难以兼顾等难点,并...彩色点画是一种从视觉上由大量小像素点构建图像的艺术技术,像素个数的多少直接影响着构图的成本。其优化选点构图方法为实现低成本打印提供了一个重要的方式。目前,点画生成存在着多通道采样点难以均匀分布,颜色层次难以兼顾等难点,并耗费大量的计算成本。对此,提出了一种基于超像素自适应聚类和线性规划最优选点的彩色点画生成方法,该方法在初步超像素划分图像的基础上,使用基于颜色密度峰值的自适应聚类方法得到最佳聚类个数,并进一步划分子聚类,然后根据每个子聚类的颜色均值作为子聚类内部选点的最佳间隔距离,在选点的同时依据SSIM指标,建立目标优化模型,通过数学优化器Gurobi实现模型选点,使点保留最少个数的目标基础上,同时保持聚类内部分布均匀和颜色渐变层次,以提高所生成的点画图像的可视化效果。实验结果表明,本文算法极大地降低了像素个数并在生成的点画的平均结构相似性(mean structural similarity index measure,SSIM)、峰值信噪比(peak signal to noise ratio,PSNR)等评价指标方面均优于当前方法。展开更多
文摘In order to study the preferred skin color for printing images,two CMYK images from ISO 400 and one from iStock,including five skin color images of East Asian females was selected in this study.The images were adjusted with the CMYK printing ink volume variation of the single,double and triple channels in the given 280%total ink limit conditions.A larger number of color vision normal observers were organized to carry out the color preference evaluation experiment,and the selected preferred skin colors were analyzed.The distribution range of the chromaticity values for skin color images were obtained and the results indicated that there are three regions for printing skin color preferences,and the observers have a memory preference for brighter,fairer skin colors in young female and a reddish skin colors in girl,which can provide the guidance for color adjustment of printed skin color images.
文摘In the printing industry,the common method of coloring relies on inks,which contains amounts of chemical agents,causing environment pollution.However,structural color achieves coloration through the refraction and diffraction of light by periodic structure,offering eco-friendly and fade-resistant advantages,as well as colorful.In this study,screen printing was used to create patterned mask on paper substrates.Then,coated SiO_(2)microspheres on the mask to create structural color patterns with angle-dependent color characteristics.The patterns showed color changes from rose-red to orange to green by changing the viewing angle.By changing the color grayscale,the absorption of stray light by the substrate was enhanced,thereby the brightness and saturation of the structural color improved too.This method is simple,cost-effective,and environmentally friendly,and it has highly promising for the application in printing and anti-counterfeiting.
文摘彩色点画是一种从视觉上由大量小像素点构建图像的艺术技术,像素个数的多少直接影响着构图的成本。其优化选点构图方法为实现低成本打印提供了一个重要的方式。目前,点画生成存在着多通道采样点难以均匀分布,颜色层次难以兼顾等难点,并耗费大量的计算成本。对此,提出了一种基于超像素自适应聚类和线性规划最优选点的彩色点画生成方法,该方法在初步超像素划分图像的基础上,使用基于颜色密度峰值的自适应聚类方法得到最佳聚类个数,并进一步划分子聚类,然后根据每个子聚类的颜色均值作为子聚类内部选点的最佳间隔距离,在选点的同时依据SSIM指标,建立目标优化模型,通过数学优化器Gurobi实现模型选点,使点保留最少个数的目标基础上,同时保持聚类内部分布均匀和颜色渐变层次,以提高所生成的点画图像的可视化效果。实验结果表明,本文算法极大地降低了像素个数并在生成的点画的平均结构相似性(mean structural similarity index measure,SSIM)、峰值信噪比(peak signal to noise ratio,PSNR)等评价指标方面均优于当前方法。
