Halftone Technology Research Articles

An Application of Deep Learning Technology in The Recognition of Forged Documents with Color Laser Printing

<p>Advanced laser printing technology is now widely used in daily life and at work. Because laser printers are so easy to obtain and use, they have also become a popular method for criminals to forge important documents like currency, securities, and certificates. To obtain evidence for document forgery, traditional forensics use chemical analysis of ink, but the cost is high. Laser color printing uses halftone technology. This technology combines the CMYK printing colors’ halftone screens at their respective angles. When correctly superimposed, they will form a moiré pattern. And the moiré pattern of a color block differs depending on the printer brand or model. This paper will use deep learning to create an image recognition model that can quickly classify forged documents by combining image processing, data augmentation, and transfer learning. The experimental results are examined using indicators of accuracy, precision, recall, F1-score, and PR curve. The results show that ResNet-50 has the best performance and can be used to detect document forgery. The study’s findings will be useful for future criminal investigators and forensic personnel in their work.</p> <p> </p>

Inverse Halftoning Based on Weighted Nuclear Norm Minimization

The inverse halftoning technology refers to restoring a continuous-toned image from a halftoned image with only bi-level pixels. However, recovering the continuous images from their halftoned ones is normally ill-posed, which makes the inverse halftoning algorithm very challenging. In this paper, we propose an optimization model with two alternate projections (TAP) for image inverse halftoning under the weighted nuclear norm minimization (WNNM) framework. The main contributions are twofold. First, the WNNM nonlocal regularization term is established, which offers a powerful mechanism of nonlocal self-similarity to ensure a more reliable estimation. Second, the alternate minimization projections are formulated for solving the image inverse halftoning, which reconstructs the continuous-toned image without destroying the image details and structures. The experimental results showed that the proposed method outperformed the state of the arts in terms of both objective measurements and subjective visual performance. The codes and constructed models are available at: https://github.com/juneryoung2022/IH-WNNM.

Synthesis and performance of ZnO quantum dots water-based fluorescent ink for anti-counterfeiting applications

In this study, the ZnO quantum dots (QDs) water-based fluorescent anti-counterfeiting ink was prepared with the polyvinylpyrrolidone (PVP) content of 0.15–0.17 g/mL, the ZnO QDs concentration of 4% and water as the solvent, which has good fluorescence, printability and resistance. According to the halftone technology, fluorescence quenching of the ZnO QDs by acid, and acid resistance of the organic fluorescent ink, a high-quality anti-counterfeiting method of fluorescent discoloration was proposed. The QDs ink has broad application prospects in the field of anti-counterfeiting green packaging.

Principle Analysis of New Halftone Technology that Improves Robustness to Misregistration

Principle Analysis of New Halftone Technology that Improves Robustness to Misregistration

New Halftone Technology that Improves Robustness to Misregistration

New Halftone Technology that Improves Robustness to Misregistration

Side by Side: The Halftone’s Visual Culture of Pragmatism

Charles S. Peirce’s late-nineteenth-century semiotic theory has long been considered one of the key frameworks for analysing the photograph as a visual sign. This article, however, proposes a closer look at Peirce’s contemporaneous philosophy of pragmatism as a fundamental component of the visual, cultural, and intellectual context within which the photographic halftone first emerged. When, exactly, did it begin to matter if a photographic image made up of a certain arrangement of graphic marks was read differently from a photographic image made up of a different arrangement of graphic marks? Such pragmatist questions were crucial to the early reception of halftone reproductions, which were often integrated into illustrated magazines as simply one element within an already diverse array of graphic codes. Turning to Jacob Riis’s How the Other Half Lives (1890) as a case study, this article argues that reading the halftone as a chiefly photographic sign was not in fact an inevitable outcome of its introduction into the illustrated press in the 1880s and 1890s, but required instead a constant negotiation of both visual and conceptual imprecision – an imprecision eventually smoothed over in favour of an association of halftone technology with photographic ontology by the early twentieth century.

Color transform analysis for microscale image segmentation to study halftone model parameters

Abstract This article presents a comprehensive study of 30 color transforms to accurately segment images of halftone prints and thus calculating the parameters of a color prediction model. The transforms are evaluated combining three metrics: the model accuracy,Otsu’s discriminant, and correlation coefficients of histograms. Hierarchical cluster analysis is applied to determine the thresholds to segment the image histogram into paper, ink and mixed area. Among the 30 different transforms discussed in this article, 21 channels are of 7 color space models (RGB, CMYK, CIELAB, HSV, YIQ, YCbCr, and XYZ) and the other 9 channels are specially designed. Notable increase in model accuracy validates the segmentation accuracy and the necessity of choosing the appropriate transform. A set of 180 halftone images of different print properties (such as paper, halftone, ink and printing technology) has been used for the evaluation. It is found that, the most appropriate transform depends on the type of primary ink, but the corresponding transforms in CMYK color space model have shown consistent performance. CMYK-C, XYZ-Y and LAB-B are the best transforms for Cyan, Magenta and Yellow ink color respectively. YIQ-I and HSV-S are good candidates if a single transform is to be chosen for all primary ink colors.

The Creative Application of Halftone Technology

This paper has designed several creative application of Halftone stippling for the convenience of digital processing. It processes images to gain stippling images with different effects by using AM and FM; it also produces 3D Halftone art based on pits effect and raised effect of Relief; Besides, the paper also analyzes the processing method of stippling with paper-cutting effect and the center point’s homogenization treatment with Voronoi diagram. With easy and simple processing, the methods proposed in this paper can be used widely in such areas as landscape, wall decoration, product design, toy design and so on.

Matisse's sculpture: the pinup and the primitive

Long perceived as a side pursuit to his celebrated painting career, Henri Matisse's sculpture receives an overdue critical examination in this book. Beginning in 1906, soon after the artist acquired his first African sculpture, Matisse found inspiration in erotic and ethnographic photography, which had become inexpensively mass-produced thanks to advances in halftone technology. Working with these two radically different depictions of the body-one hand carved, the other mechanically made-was a foundational method for Matisse and crucial to the development of his pre-World War I abstraction. Far from a simple narrative of the artist discovering Africa, the highly original readings of Matisse's Sculpture plot new coordinates of study for early 20th-century primitivism. It examines the larger constructs of thought at the time, with a penetrating analysis of anthropology, popular erotica, and the visual culture of French colonialism. In addition, the book repositions Matisse's sculptural practice, particularly in regard to its investigations of race and sexuality, as a cornerstone of his prolific career.

New extended visual cryptography schemes with clearer shadow images

Visual cryptography scheme (VCS) encodes a visual information (pictures, text, etc.) into several noise-like shadow images. In VCS, each shadow image can be made on a transparency. By stacking transparencies and stack them on an overhead projector, we can visually decode the secret through human visual system without the assistance of any hardware or computation. However, noise-like shadows of VCS were suspected to censors and difficult for identification and management. Therefore, the extended VCS (EVCS) with meaningful shadow images had been proposed to address this problem of suspicion. In this paper, we employ a digital halftoning technology to propose a new EVCS whose shadow images are clearer in comparing with existing EVCSs.

Conformal optical elements for correcting wavefront distortions in YAG : Nd3+ active elements

Correction of the wavefront is studied for the light beam passing wide-aperture YAG : Nd3+ single-crystal rods, which are used as active elements in high-power solid-state lasers. A nonideal character of the crystal structure is responsible for the deformation of the wavefront of passing radiation. By using the halftone technology we have developed conformal aberration correctors capable of compensating rod nonuniformities and reducing the laser radiation divergence by an order of magnitude. The results obtained make it possible to employ optically nonuniform active elements inlaser constructions.

An Improved Design of Stochastic Halftoning without Error Diffusion for Raster Image Processor

The performance of modern printing machine depends heavily upon the raster image processor (RIP) whereof it is equipped with. The conventional digital halftoning technology used in RIP is characterized as error diffusion, which is suitable for imaging machines with low resolutions, often resulting in correlated artifacts and transient edges. We report an innovative stochastic halftoning method without error diffusion for RIP by using an optimized random number generator (RNG). The RIP system we proposed has simple computation and stochastic features of ink spots. This research is supportive of enhancing raster image quality oriented to printing machines with high physical resolutions.

(2,n) secret sharing scheme for gray and color images based on Boolean operation

Traditional secret sharing (SS) schemes can reconstruct the secret precisely, but have high com- putation complexity. Visual secret sharing (VSS) schemes use human visual system to reconstruct the secret without cryptographic computation, but have pixel expansion and loss of contrast. Wang et al. proposed a (2,n)-SS scheme for binary images based on Boolean operation, which has low computation complexity, no pixel expansion and the contrast is 1/2. In this paper, we first construct an r runs (2,n)-SS scheme to improve the contrast of Wang et al.'s binary (2,n)-SS scheme. Then we present two approaches to construct r runs (2,n)-SS schemes for grayscale image and color image. The two approaches are both based on Boolean operation, while one approach uses halftone technology and the other uses bit level processing. These proposed schemes have low computation complexity and almost ideal contrast.

基于布尔运算的(2, <italic>n</italic>) 秘密共享方案

Traditional secret sharing (SS) schemes can reconstruct the secret precisely, but have high computa- tion complexity. Visual secret sharing (VSS) schemes use human visual system to reconstruct the secret without cryptographic computation, but have pixel expansion and loss of contrast. Wang et al. proposed a (2, n )-SS scheme for binary images based on Boolean operation, which has low computation complexity, no pixel expansion and the contrast is 1/2. In this paper, we first construct a r runs (2, n )-SS scheme to improve the contrast of Wang et al.s binary (2, n )-SS scheme. Then we present two approaches to construct r runs (2, n )-SS schemes for grayscale image and color image. The two approaches are both based on Boolean operation, while one approach uses halftone technology and the other uses bit level processing. These proposed schemes have low computation complexity and almost ideal contrast.

'Abstract idea' exception to patent-eligible subject matter clarified

'Abstract idea' exception to patent-eligible subject matter clarified

Pattern encoding method of visual 2D barcode

The authors proposed a new pattern encoding method of the visual 2D barcode based on halftone technology and texture features in halftone images. Combining the similarity of halftone texture with the distribution of encoded information in code-image, the authors also defined code-patterns to denote 0 and 1 and carried on pattern replacement to encode with the principle of consistency of local gray level. The experimental results show that the proposed method improves the encoding capacity and visual effect of coded images.

Hiding a secret colour image in two colour images

Visual cryptography is different from traditional cryptography. That is, neither time-consuming computation nor complex cryptographic knowledge is needed. Stacking is the only operation required to recover a secret image, and the individual image does not give the hackers any information about the secret image. None of researches tried to deal with meaningful colour share transparencies. Hence, two methods are proposed for hiding a colour image in two meaningful colour share transparencies in this paper. To achieve this goal, the colour decomposition approach and halftone technology are first applied to cope with secret colour images. Then the concept of the human visual system is utilized to generate two colour meaningful sharing transparencies. To support various applications, two variants are presented. The first proposed method, method-1, is suitable for simple colour images, and the second, method-2, provides better visibility of complex colour images.

Refractive micro-optics fabrication with a 1-D binary phase grating mask applicable to MOEMS processing

We present a new photomask technology capable of forming a continuous rotationally symmetric microstructure in thick photoresist. This technique eliminates many of the drawbacks of grayscale and half-tone masking technology. A binary phase grating of pi phase depth on a transparent quartz mask plate is fabricated in PMMA resist using an e-beam direct writing technique. When the phase mask is used in the stepper, an analog intensity profile is created on the wafer. The period is constrained, allowing for control of the zero-order in the stepper. The duty cycle of the phase gratings can be varied in such a way to provide the proper analog intensity profile for a wide range of micro-optics on the photoresist. The design, analysis, and fabrication procedures of this technique are discussed. This processing technique can be applied to many MOEMS devices that require refractive elements for optical processing. The method greatly simplifies the device process, reducing the cost and improving the device yield.

The Fundamentals of Halftoning Technology in Printing Industry and Their Current Topics

The Fundamentals of Halftoning Technology in Printing Industry and Their Current Topics

1897: American Journalism's Exceptional Year

This article directs attention to the remarkable developments of 1897 and argues that year merits recognition as a pivotal moment in the trajectory of American journalism. In presenting that case, the article pursues a methodological frame—a single-year study—that has been little tested in journalism history, a field that leading scholars have criticized for resistance to fresh ways of considering journalism's past. The notable developments of 1897 included the publication of perhaps the most famous editorial in American journalism, the diffusion of the enduring epithet “yellow journalism,” and a breakthrough in applying half-tone technology in daily newspapers. It also was the year when a choice between rival visions for the future of American journalism crystallized between the activist ethos of the New York Journal and the detached, fact-based antithesis of that genre, the New York Times.