Effects of Dot Configuration on Color Reproduction and Anti-counterfeiting Features

2020 ◽  
Author(s):  
Raymond Chiang ◽  
Pei-Li Sun
Keyword(s):  
Screening Method ◽  
Error Diffusion ◽  
Color Management ◽  
Shape Error ◽  
Color Reproduction ◽  
Two Stage ◽  
Color Quality ◽  
Raster Image ◽  
Color Differences ◽  
Continuous Tone

This study represents an attempt to solve the problem of color reproduction and identification for the prevention of stamp forgery. Generally, printed images are converted to halftone dot patterns by using a raster image processor. The amplitude-modulated dots of each separated color plane have a consistent shape such as conventional round, square, ellipse, or diamond shape; error diffusion occurs in frequency-modulated dots. To achieve anti-counterfeiting properties for stamp reproduction, two methods are proposed to obtain difficult-to-replicate dot structures and to provide corresponding color management methods. The first method involves arranging different dot shapes in different areas of an image. Color consistency is achieved using a virtual gray balance method. However, color differences are visible when two dot types are assigned to adjacent areas with similar colors. The second method is a two-stage screening method. The first screening stage defines different micro-regions in the image, which are then combined with the continuous-tone image again in the second screening step to assign different dot patterns to different micro-regions. This approach not only provides anti-counterfeiting ability but also ensures color consistency and allows controlling color quality using one ICC profile.

Texture-aware Error Diffusion Algorithm for Multi-level Digital Halftoning

2020 ◽  
Vol 64 (5) ◽  
pp. 50410-1-50410-9
Author(s):  
Donghui Li ◽  
Takuma Kiyotomo ◽  
Takahiko Horiuchi ◽  
Midori Tanaka ◽  
Kaku Shigeta
Keyword(s):  
Digital Printing ◽  
Diffusion Method ◽  
Error Diffusion ◽  
Digital Halftoning ◽  
Halftone Image ◽  
Processing Theory ◽  
Raster Image ◽  
Continuous Tone ◽  
Multi Level ◽  
Halftone Images

Abstract Digital halftoning is a technique for converting a continuous-tone image into a quantized image to reproduce it on a digital printing device. Error diffusion (ED) is an algorithm that has proven to be effective for the halftoning process, and it has been widely applied to digital printing tasks. However, in images reproduced using conventional ED algorithms based on the signal processing theory, the texture of objects is often lost. In this study, we propose a texture-aware ED algorithm for multi-level digital halftoning. First, we generate multiple mapped images with different brightness levels through nonlinear transformation. For each mapped image, we adopt a texture-aware binary error diffusion method to obtain multiple halftone images. Finally, we generate a multi-level halftone image from the multiple halftone images. We test the algorithm on an actual printer, compare the results with those of the current raster image processor software and classical ED algorithms, and observe that our algorithm outputs better results.

The Study on Color Quality Attributes of IMR with PET on White Ink by UV Inkjet

2014 ◽  
Vol 1004-1005 ◽  
pp. 799-802 ◽  
Author(s):  
Chang Lang Chen ◽  
Yu Tung Chang ◽  
Sheng Hao Taso ◽  
Weichieh Hsu
Keyword(s):  
Inkjet Printing ◽  
Screen Printing ◽  
Quality Attributes ◽  
Gravure Printing ◽  
Printing Process ◽  
Color Quality ◽  
Study Results ◽  
Color Differences ◽  
Pet Film ◽  
Better Than

The In-Mold Roller is a revolutionary printing process by which objects are 3D decorated. Products decorated by In-Mold Roller are waterproof and protected from fading. What’s more, these kinds of decorations strongly increase the beauty, desirability and value of the objects. The In-Mold Roller is now using either of gravure printing and screen printing to print PET film. However, there are some problems with these two techniques. This research is to investigate potential usages of combining In-Mold Roller with digital UV inkjet printing in 3D decoration, e.g. in personalized printing services. Study results found that when the coverage and the resolution of inkjet printing become higher, the SIDs will become higher as well. When transferred to ABS, SIDs in each combination will increase. Each combination of inkjet conditions, with the isolation of white ink, color differences are less variant. TVIs of white ink decrease 30% to 40% halftone and display in “M” type. In print contrast, C and K colors of each combination are better than M and Y colors. After transferred into print contrast, each combination of PC will be higher about 2 to5. When transferred to ABS, color variances of each combination are not huge, and color differences are about 3to5.

A Graphic/Picture Classification Method Based on Spatial Characteristics of Colors

2012 ◽  
Vol 262 ◽  
pp. 31-35
Author(s):  
Sheng Yan Cai ◽  
Xuan Nie ◽  
Shu Qin Guo
Keyword(s):  
Discriminant Analysis ◽  
Classification Performance ◽  
Classification Method ◽  
Color Management ◽  
Essential Difference ◽  
Classification Rules ◽  
Color Reproduction ◽  
Color Distribution ◽  
Color Characteristics ◽  
Different Color

In order to get optimum color reproduction results on different color devices in color management, a proper rendering intent should be selected according to color characteristics of the image. In terms of differences on color characteristics, images could be classified into synthetic graphics and natural pictures. Different rendering intent should be applied on graphics and pictures. So graphic/picture automatic classification becomes a fundamental task of color management intellectualization. Characteristics on color distribution of a large number of images have been researched in our experiments. Then it is confirmed that the essential difference between graphic and picture is the characteristics on color distribution in the neighborhood of images rather than the number of colors or the volume of image gamut. Thus, the features which have distinct ability to show the differences could be used to build classification rules. In this paper, several mathematical features of image are extracted and selected by their classification performance. Based on these features, the discriminant analysis is adopted to build up discriminated functions. Finally, the accuracy of the functions has been tested and the precision is 96.75%.

Comparative Study of Ink-Jet Color Proofing Systems Based on Color Management

2014 ◽  
Vol 910 ◽  
pp. 405-409
Author(s):  
Chang Xian Cheng ◽  
Yan Mei Liang
Keyword(s):  
Color Difference ◽  
Management Systems ◽  
Color Management ◽  
Color Matching ◽  
Color Gamut ◽  
Matching Effect ◽  
Ink Jet ◽  
Color Differences ◽  
Jet Printing ◽  
Different Color

Abstract. In order to study the color matching effect of ink-jet printing press under different color management systems. I applied EFI and ORIS series color management soft wares separately to the same Epson ink-jet printer and optimized the proofing with exploring the most reasonable settings. After that, I will compare the gamut and color difference in a special color management module, and also make a contrast with a standard color gamut to check the color matching effect. The results show that the average color differences of the two soft wares are all below 1.0. However, differences measured by ORIS is lower, falling to 0.5 only, which implies the proofing under ORIS color management is more similar to the presswork and more stable.

Spectral color reproduction minimizing spectral and perceptual color differences

2008 ◽  
Vol 33 (6) ◽  
pp. 494-504 ◽  
Author(s):  
Jérémie Gerhardt ◽  
Jon Y. Hardeberg
Keyword(s):  
Color Reproduction ◽  
Color Differences

scholarly journals Tool Path Design of the Counter Single Point Incremental Forming Process to Decrease Shape Error

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4719
Author(s):  
Kyu-Seok Jung ◽  
Jae-Hyeong Yu ◽  
Wan-Jin Chung ◽  
Chang-Whan Lee
Keyword(s):  
Sheet Metal ◽  
Tool Path ◽  
Incremental Forming ◽  
Single Point ◽  
Optimization Method ◽  
Single Point Incremental Forming ◽  
Shape Error ◽  
Forming Process ◽  
Two Stage ◽  
Shape Errors

Incremental sheet metal forming can manufacture various sheet metal products without a dedicated punch and die set. In this study, we developed a two-stage incremental forming process to decrease shape errors in the conventional incremental forming process. The forming process was classified into the first single point incremental forming (1st SPIF) process for forming a product and the counter single point incremental forming (counter SPIF) process to decrease shape error. The counter SPIF gives bending deformation in the opposite direction. Furthermore, the counter SPIF compensates for shape errors, such as section deflection, skirt spring-back, final forming height, and round. The tool path of the counter SPIF has been optimized through a relatively simple optimization method by modifying the tool path of the previous step. The tool path of the 1st SPIF depends on the geometry of the product. An experiment was performed to form a circular cup shape to verify the proposed tool path of the 1st and counter SPIF. The result confirmed that the shape error decreased when compared to the conventional SPIF. For the application, the ship-hull geometry was adopted. Experimental results demonstrated the feasibility of the two-stage incremental forming process.

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