Towards High-Resolution Copy-Evident Ceramic Tiles: A Deep Learning Framework for Halftoning and Watermarking

Ceramic art is essential in interior design and decoration, and making exquisite ceramic tiles imposes strict requirements for inkjet printing technology. High-resolution ceramic tiles are often produced through inkjet printing, in which the input images are converted into a halftone format. However, traditional binary halftoning techniques cannot produce high-resolution images for the ensuing printing process. Given that the processes of inkjet printing and high-temperature firing of ceramic tiles are a highly complex nonlinear system, and existing halftoning methods pose intractable problems, including inconsistent textures and color deviations. Based on a modified U-Net model and a modified error diffusion algorithm, we propose a multilevel halftoning method, which is capable of converting color-separation images of ceramic tiles into high-resolution halftone images. To deter copyright infringement, we further apply an ad hoc invisible watermarking method for halftone images. In this paper, we propose a four-stage framework: (1) A self-built dataset is used to solve non-convergence and overfitting problems caused by the unbalanced samples and non-uniqueness of halftone images. (2) A modified U-Net model is trained on the self-built dataset and applied to the ceramic-tile images. (3) An improved error diffusion algorithm is used to calibrate and convert the predicted continuous-tone transition images into multilevel halftone images for inkjet printing. (4) A invisible and robust watermark is embedding algorithm towards halftone images is proposed for copyright protection. Experimental results show that our methodology is effective for performing the color-to-halftone transformation and identifying the copyright.

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

Journal of Imaging Science and Technology ◽

10.2352/j.imagingsci.technol.2020.64.5.050410 ◽

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.

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Reading the bed morphology of a mountain stream: a geomorphometric study on high-resolution topographic data

Hydrology and Earth System Sciences ◽

10.5194/hess-14-393-2010 ◽

2010 ◽

Vol 14 (2) ◽

pp. 393-405 ◽

Cited By ~ 24

Author(s):

S. Trevisani ◽

M. Cavalli ◽

L. Marchi

Keyword(s):

High Resolution ◽

Ad Hoc ◽

Flow Direction ◽

Spatial Scales ◽

Mountain Stream ◽

Topographic Data ◽

The Difference ◽

Morphological Differences ◽

High Level ◽

Local Anomalies

Abstract. High-resolution topographic data expand the potential of quantitative analysis of the earth surface, improving the interpretation of geomorphic processes. In particular, the morphologies of the channel beds of mountain streams, which are characterised by strong spatial variability, can be analysed much more effectively with this type of data. In this study, we analysed the aerial LiDAR topographic data of a headwater stream, the Rio Cordon (watershed area: 5 km2), located in the Dolomites (north-eastern Italy). The morphology of the channel bed of Rio Cordon is characterised by alternating step pools, cascades, and rapids with steps. We analysed the streambed morphology by means of ad hoc developed morphometric indices, capable of highlighting morphological features at a high level of spatial resolution. To perform the analysis and the data interpolation, we carried out a channel-oriented coordinate transformation. In the new coordinate system, the calculation of morphometric indices in directions along and transverse to the flow direction is straightforward. Three geomorphometric indices were developed and applied as follows: a slope index computed on the whole width of the channel bed, directional variograms computed along the flow direction and perpendicular to it, and local anomalies, calculated as the difference between directional variograms at different spatial scales. Directional variograms in the flow direction and local anomalies have proven to be effective at recognising morphologic units, such as steps, pools and clusters of large boulders. At the spatial scale of channel reaches, these indices have demonstrated a satisfactory capability to outline patterns associated with boulder cascades and rapids with steps, whereas they did not clearly differentiate between morphologies with less marked morphological differences, such as step pools and cascades.

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Data hiding in halftone images with noise-balanced error diffusion

IEEE Signal Processing Letters ◽

10.1109/lsp.2003.817856 ◽

2003 ◽

Vol 10 (12) ◽

pp. 349-351 ◽

Cited By ~ 26

Author(s):

Soo-Chang Pei ◽

Jing-Ming Guo

Keyword(s):

Data Hiding ◽

Error Diffusion ◽

Halftone Images

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High-resolution electrohydrodynamic inkjet printing of stretchable metal oxide semiconductor transistors with high performance

Nanoscale ◽

10.1039/c6nr05577j ◽

2016 ◽

Vol 8 (39) ◽

pp. 17113-17121 ◽

Cited By ~ 57

Author(s):

S.-Y. Kim ◽

K. Kim ◽

Y. H. Hwang ◽

J. Park ◽

J. Jang ◽

...

Keyword(s):

High Resolution ◽

Metal Oxide ◽

Inkjet Printing ◽

High Performance ◽

Metal Oxide Semiconductor ◽

Oxide Semiconductor

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Dynamic phase control with printing and fluidic materials' interaction by inkjet printing an RF sensor directly on a stereolithographic 3D printed microfluidic structure

Lab on a Chip ◽

10.1039/d1lc00419k ◽

2021 ◽

Author(s):

Eiyong Park ◽

Sungjoon Lim

Keyword(s):

Surface Modification ◽

High Resolution ◽

Inkjet Printing ◽

Phase Control ◽

High Conductivity ◽

Dynamic Phase ◽

3D Printed ◽

Rf Electronics ◽

Microfluidic Structure

RF electronics is inkjet-printed directly onto a 3D printed microfluidic structure using surface modification for the high conductivity, high resolution, and enhanced the interaction between a RF part and a fluid material.

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High-resolution organic field-effect transistors manufactured by electrohydrodynamic inkjet printing of doped electrodes

Journal of Materials Chemistry C ◽

10.1039/d0tc02508a ◽

2020 ◽

Vol 8 (43) ◽

pp. 15219-15223

Author(s):

Jing Zhang ◽

Bowen Geng ◽

Shuming Duan ◽

Congcong Huang ◽

Yue Xi ◽

...

Keyword(s):

High Resolution ◽

Inkjet Printing ◽

Field Effect ◽

Field Effect Transistors ◽

Organic Field Effect Transistors ◽

Top Contact

A top-contact, sub-5 μm resolution OFET is realized using inkjet printed electrodes with different F4-TCNQ doping concentrations.

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Watermark Embedding for Multiscale Error Diffused Halftone Images by Adopting Visual Cryptography

International Journal of Digital Crime and Forensics ◽

10.4018/ijdcf.2015010103 ◽

2015 ◽

Vol 7 (1) ◽

pp. 51-68 ◽

Cited By ~ 2

Author(s):

Yuanfang Guo ◽

Oscar C. Au ◽

Ketan Tang

Keyword(s):

Image Watermarking ◽

Visual Cryptography ◽

Superior Performance ◽

Error Diffusion ◽

Printing Industry ◽

Halftone Image ◽

Watermark Embedding ◽

Simple Implementation ◽

Exclusive Or ◽

Halftone Images

Error Diffusion has been widely adopted in the printing industry due to its good visual quality and simple implementation. However, error diffusion still possesses its own deficiencies. Thus multiscale error diffusion (MED) has been developed, and this method outperforms traditional error diffusion according to extensive research results. The majority of previous halftone image watermarking techniques cannot be directly applied to MED halftone images. Since there is no halftone visual watermarking (HVW) method for MED halftone images in existing methods, we propose the first HVW method for MED halftone images, Copyright Protecting Multiscale Error Diffusion (CoP-MED), in this paper. By adopting the visual cryptography principle, CoP-MED can effectively embed a secret pattern into two MED halftone images, where the secret pattern can be decoded clearly by simply overlaying the two stego halftone images or performing not-exclusive-or operation between them. Parameter selection is also discussed based on the experimental results. Later, in comparison tests, CoP-MED shows superior performance compared to existing works.

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