High-resolution multi-color printing relies upon pixelated optical nanostructures,which is crucial to promote color display by producing nonbleaching colors,yet requires simplicity in fabrication and dynamic switching...High-resolution multi-color printing relies upon pixelated optical nanostructures,which is crucial to promote color display by producing nonbleaching colors,yet requires simplicity in fabrication and dynamic switching.Antimony trisulfide(Sb_(2)S_(3))is a newly rising chalcogenide material that possesses prompt and significant transition of its optical characteristics in the visible region between amorphous and crystalline phases,which holds the key to color-varying devices.Herein,we proposed a dynamically switchable color printing method using Sb_(2)S_(3)-based stepwise pixelated Fabry-Pérot(FP)cavities with various cavity lengths.The device was fabricated by employing a direct laser patterning that is a less timeconsuming,more approachable,and low-cost technique.As switching the state of Sb_(2)S_(3) between amorphous and crystalline,the multi-color of stepwise pixelated FP cavities can be actively changed.The color variation is due to the profound change in the refractive index of Sb_(2)S_(3) over the visible spectrum during its phase transition.Moreover,we directly fabricated sub-50 nm nano-grating on ultrathin Sb_(2)S_(3) laminate via microsphere 800-nm femtosecond laser irradiation in far field.The minimum feature size can be further decreased down to~45 nm(λ/17)by varying the thickness of Sb_(2)S_(3) film.Ultrafast switchable Sb_(2)S_(3) photonic devices can take one step toward the next generation of inkless erasable papers or displays and enable information encryption,camouflaging surfaces,anticounterfeiting,etc.Importantly,our work explores the prospects of rapid and rewritable fabrication of periodic structures with nano-scale resolution and can serve as a guideline for further development of chalcogenide-based photonics components.展开更多
The cellular Yule-Nielson spectral Neugebauer （CYNSN） model to characterize a typical CMYK （i.e.,cyan,magenta,yellow,and black） 4-ink color printer is presented.By reconstructing spectral reflectance,models with h...The cellular Yule-Nielson spectral Neugebauer （CYNSN） model to characterize a typical CMYK （i.e.,cyan,magenta,yellow,and black） 4-ink color printer is presented.By reconstructing spectral reflectance,models with high accuracy of spectral and colorimetric predictions are built.A novel cell-searching algorithm is proposed and used together with the iteration method to invert the cellular Neugebauer model efficiently.Large numbers of high quality hardcopy samples are produced to evaluate model performance and prove the feasibility of the algorithm.The spectral-based model performs better compared with the usual model based on CIE1931 XYZ tristimulus values.展开更多
To over come the drawbacks existing in current measurement methods for detecting and controlling colors in printing process, a new medal for color separation and dot recognition is proposed from a view of digital imag...To over come the drawbacks existing in current measurement methods for detecting and controlling colors in printing process, a new medal for color separation and dot recognition is proposed from a view of digital image processing and patter recognition. In this model, firstly data samples are collected from some color patches by the Fuzzy C-Means （FCM） method; then a classifier based on the Cerebellar Model Articulation Controller （CMAC） is constructed which is used to recognize color pattern of each pixel in a microscopic halftone image. The principle of color separation and the algorithm model are introduced and the experiments show the effectiveness of the CMAC-based classifier as opposed to the BP network.展开更多
3D printing is a promising technology used in the fabrication of complex oral dosage delivery pharmaceuticals.This study first reports an innovative color jet 3D printing(CJ-3DP)technology to produce colorful cartoon ...3D printing is a promising technology used in the fabrication of complex oral dosage delivery pharmaceuticals.This study first reports an innovative color jet 3D printing(CJ-3DP)technology to produce colorful cartoon levetiracetam pediatric preparations with high accuracy and reproducibility.For this study,the ideal printing ink consisted of 40%(v/v)isopropanol aqueous solution containing 0.05%(w/w)polyvinylpyrrolidone and 4%(w/w)glycerin,which was satisfied with scale-up of the production.The external and internal spatial structures of the tablets were designed to control the appearance and release,and cartoon tablets with admirable appearances and immediate release characteristics were printed.The dosage model showed a good linear relationship between the model volume and the tablet strength(r>0.999),which proved the potential of personalized administration.The surface roughness indicated that the appearance of the CJ-3DP tablets was significantly better than the first listed 3D printed drug(Spritam R).Moreover,the scanning electron microscopy and porosity results further showed that the tablets have a structure of loose interior and tight exterior,which could ensure good mechanical properties and rapid dispersion characteristics simultaneously.In conclusion,the innovative CJ-3DP technology can be used to fabricate personalized pediatric preparations for improved compliance.Due to the stable formulation and fabrication process,this technology has the potential in scale-up production.展开更多
Color image printing technique on ink jetting printer is introduced.Color shading method such as dithering,Amplitude Modulation(AM)screening and Frequency Modulation(FM)screening is presented.Some solutions to the pro...Color image printing technique on ink jetting printer is introduced.Color shading method such as dithering,Amplitude Modulation(AM)screening and Frequency Modulation(FM)screening is presented.Some solutions to the problems with FM screening are given. An application program under Windows is developed.展开更多
Through discussing the color matching technology and its application in printing industry the conventional approaches commonly used in color matching, and the difficulties in color matching, a nonlinear color matching...Through discussing the color matching technology and its application in printing industry the conventional approaches commonly used in color matching, and the difficulties in color matching, a nonlinear color matching model based on two step learning is established by finding a linear model by learning pure color data first and then a nonlinear modification model by learning mixed color data. Nonlinear multiple regression is used to fit the parameters of the modification model. Nonlinear modification function is discovered by BACON system by learning mixture data. Experiment results indicate that nonlinear color conversion by two step learning can further improve the accuracy when it is used for straightforward conversion from RGB to CMYK. An improved separation model based on GCR concept is proposed to solve the problem of gray balance and it can be used for three to four color conversion as well. The method proposed has better learning ability and faster printing speed than other historical approaches when it is applied to four color ink jet printing.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
基金support from the National Key Research and Development Program of China (2020YFA0714504,2019YFA0709100).
文摘High-resolution multi-color printing relies upon pixelated optical nanostructures,which is crucial to promote color display by producing nonbleaching colors,yet requires simplicity in fabrication and dynamic switching.Antimony trisulfide(Sb_(2)S_(3))is a newly rising chalcogenide material that possesses prompt and significant transition of its optical characteristics in the visible region between amorphous and crystalline phases,which holds the key to color-varying devices.Herein,we proposed a dynamically switchable color printing method using Sb_(2)S_(3)-based stepwise pixelated Fabry-Pérot(FP)cavities with various cavity lengths.The device was fabricated by employing a direct laser patterning that is a less timeconsuming,more approachable,and low-cost technique.As switching the state of Sb_(2)S_(3) between amorphous and crystalline,the multi-color of stepwise pixelated FP cavities can be actively changed.The color variation is due to the profound change in the refractive index of Sb_(2)S_(3) over the visible spectrum during its phase transition.Moreover,we directly fabricated sub-50 nm nano-grating on ultrathin Sb_(2)S_(3) laminate via microsphere 800-nm femtosecond laser irradiation in far field.The minimum feature size can be further decreased down to~45 nm(λ/17)by varying the thickness of Sb_(2)S_(3) film.Ultrafast switchable Sb_(2)S_(3) photonic devices can take one step toward the next generation of inkless erasable papers or displays and enable information encryption,camouflaging surfaces,anticounterfeiting,etc.Importantly,our work explores the prospects of rapid and rewritable fabrication of periodic structures with nano-scale resolution and can serve as a guideline for further development of chalcogenide-based photonics components.
文摘The cellular Yule-Nielson spectral Neugebauer （CYNSN） model to characterize a typical CMYK （i.e.,cyan,magenta,yellow,and black） 4-ink color printer is presented.By reconstructing spectral reflectance,models with high accuracy of spectral and colorimetric predictions are built.A novel cell-searching algorithm is proposed and used together with the iteration method to invert the cellular Neugebauer model efficiently.Large numbers of high quality hardcopy samples are produced to evaluate model performance and prove the feasibility of the algorithm.The spectral-based model performs better compared with the usual model based on CIE1931 XYZ tristimulus values.
文摘To over come the drawbacks existing in current measurement methods for detecting and controlling colors in printing process, a new medal for color separation and dot recognition is proposed from a view of digital image processing and patter recognition. In this model, firstly data samples are collected from some color patches by the Fuzzy C-Means （FCM） method; then a classifier based on the Cerebellar Model Articulation Controller （CMAC） is constructed which is used to recognize color pattern of each pixel in a microscopic halftone image. The principle of color separation and the algorithm model are introduced and the experiments show the effectiveness of the CMAC-based classifier as opposed to the BP network.
基金This work was supported by the National Natural Science Foundation of China(No.82073793)the National Major Science and Technology Projects of China(No.2018ZX09721003-007/No.2018ZX09J18107).
文摘3D printing is a promising technology used in the fabrication of complex oral dosage delivery pharmaceuticals.This study first reports an innovative color jet 3D printing(CJ-3DP)technology to produce colorful cartoon levetiracetam pediatric preparations with high accuracy and reproducibility.For this study,the ideal printing ink consisted of 40%(v/v)isopropanol aqueous solution containing 0.05%(w/w)polyvinylpyrrolidone and 4%(w/w)glycerin,which was satisfied with scale-up of the production.The external and internal spatial structures of the tablets were designed to control the appearance and release,and cartoon tablets with admirable appearances and immediate release characteristics were printed.The dosage model showed a good linear relationship between the model volume and the tablet strength(r>0.999),which proved the potential of personalized administration.The surface roughness indicated that the appearance of the CJ-3DP tablets was significantly better than the first listed 3D printed drug(Spritam R).Moreover,the scanning electron microscopy and porosity results further showed that the tablets have a structure of loose interior and tight exterior,which could ensure good mechanical properties and rapid dispersion characteristics simultaneously.In conclusion,the innovative CJ-3DP technology can be used to fabricate personalized pediatric preparations for improved compliance.Due to the stable formulation and fabrication process,this technology has the potential in scale-up production.
文摘Color image printing technique on ink jetting printer is introduced.Color shading method such as dithering,Amplitude Modulation(AM)screening and Frequency Modulation(FM)screening is presented.Some solutions to the problems with FM screening are given. An application program under Windows is developed.
文摘Through discussing the color matching technology and its application in printing industry the conventional approaches commonly used in color matching, and the difficulties in color matching, a nonlinear color matching model based on two step learning is established by finding a linear model by learning pure color data first and then a nonlinear modification model by learning mixed color data. Nonlinear multiple regression is used to fit the parameters of the modification model. Nonlinear modification function is discovered by BACON system by learning mixture data. Experiment results indicate that nonlinear color conversion by two step learning can further improve the accuracy when it is used for straightforward conversion from RGB to CMYK. An improved separation model based on GCR concept is proposed to solve the problem of gray balance and it can be used for three to four color conversion as well. The method proposed has better learning ability and faster printing speed than other historical approaches when it is applied to four color ink jet printing.
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。
