O Projektu

Razvoj modela za povećanje efikasnosti izrade i funkcionalnosti grafičke ambalaže

Grafička tehnologija je polje iz grane tehničkih znanosti s visokim stupnjem primjenjivosti u sustavima koji se oslanjaju na tehnološke napretke u području računarskih znanosti i inženjerstva i znanosti o materijalima. Specifičnost ovog istraživačkog područja jest upravo dvosmjerna veza između digitalnog okruženja koje se odnosi na manipulaciju i obradu slikovnih informacija i „realnog“ okruženja u kojem se navedene informacije reproduciraju koristeći različite materijale. Ovo istraživanje se provodi s ciljem razvoja modela za povećanje efikasnosti izrade i funkcionalnosti grafičke ambalaže. Navedeni cilj postići će se kroz provođenje grupa aktivnosti koje bismo mogli podijeliti u četiri osnovne skupine:

  • Razvoj i evaluacija metode za zamjenu kromatskih boja akromatskom komponentom(GCR)
  • Razvoj metode za implementaciju digitalnog vodenog žiga kao sredstva zaštite grafičke reprodukcije
  • Karakterizacije grafičkih materijala i razvoj funkcionalnih premaza te analizom njihovih utjecaja karakteristika na višebojnu reprodukciju
  • Razvoj i ocjena matematičkog modela koji će povezati utjecaj elemenata modulacije slikovne informacije i karakteristika materijala te oplemenjivanja otisaka na mehanička svojstva i vizualnu percepciju reprodukcije
Motivacija
Mnogi mladi istraživači susreću se s izazovom - kako razviti svoj istraživački potencijal te izaći iz sjene svojih iskusnijih kolega. Ovaj projekt, financiran od strane Hrvatske zaklada za znanost, pružio je mogućnost rada u timu mladih istraživača. Obzirom da svaki član tima ima različite istraživačke interese i dosadašnja iskustva, ova suradnja ima veliki potencijal i nudi nova iskustva i saznanja kroz promatranje problema iz različitih kuteva te upotrebom različite metodologije. Iskustva koja ćemo steći tijekom provedbe ovog projekta kroz rješavanje različitih izazova, kako znanstvenih, tako i timskog rada, uvelike će nam pomoći u znanstvenom razvoju, a istovremeno se stvara jedan multidisciplinarni tim znanstvenika spremnih za istraživanje u području grafičkih materijala, osobito u proizvodnji ambalaže.

Pored osobnih motiva svakog člana tima, kao dio tiskarske i industrije grafičkih komunikacija, očekujemo postizanje glavnog cilja ovog projekta - povećanje efikasnosti izrade te povećanje funkcionalnosti ambalaže kroz implementaciju zaštitnih elemenata u slici te unaprjeđenja materijala za povećanje mehaničkih svojstava te vizualne percepcije.
Vijesti

Održana konferencija Ambalaža i etikete

10. studenog 2022. održana je konferencija Ambalaža i etikete, u Antonović Hotelu u Zagrebu. Konferencija je privukla više od 130 sudionika, a kao izlagač je sudjelovao i Tomislav Cigula, član M.E.G.A. tima. Naslov prezentacije profesora Cigule bio je “Nanokompozitni premazi i vodeni žig za dodatnu sigurnost ambalaže”. Sve informacije o održanoj konferenciji možete pronaći ovdje.

GRID22

Članovi M.E.G.A. tima Tomislav Cigula i Tomislav Hudika sudjelovali su na konferenciji GRID22 u Novom Sadu u Srbiji. Konferencija se održala od 3. do 5. studenog 2022. Tomislav Cigula je održao plenarno predavanje sa svojim radom pod naslovom “COATINGS IN GRAPHIC INDUSTRY”, dok je Tomislav Hudika prezentirao dva rada – “LIGHTFASTNESS OF LITHOGRAPHIC PRIMARY COLOURS COATED […]

Ambalaža i etikete

Tomislav Cigula, član M.E.G.A. tima, sudjelovat će na predstojećoj konferenciji “Ambalaža i etikete” u Antunović Hotelu u Zagrebu, 10. studenog 2022. Naslov prezentacije bit će “Nanokompozitni premazi i vodeni žig za dodatnu sigurnost ambalaže”. Sve informacije o konferenciji možete pronaći ovdje.

ACIEK Seville 2022

Ante Poljičak i Petar Branislav Jelušić, članovi M.E.G.A. tima, sudjelovali su na konferenciji ACIEK Seville 2022. Konferencija se održala od 28. do 30. lipnja 2022. godine u Sevilji, Španjolska. Naslov prezentiranog rada je “Low-frequency Data Embedding for DFT-based Image Steganography”. Poveznica do rada: LOW-FREQUENCY DATA EMBEDDING FOR DFT-BASED IMAGE STEGANOGRAPHY.
Tim
Voditelj projekta
"Opravdana kritika čini ti uslugu." Carl Sagan
Doktorand
Ante Poljičak
Istraživač
 
Petar Branislav Jelušić
Doktorand
 
Istraživač
Istraživač
"Kad matematički zakoni imaju veze sa stvarnošću, nisu pouzdani; a kad su pouzdani, nemaju veze sa stvarnošću."
 Albert Einstein
Istraživač
Publikacije

Low-Frequency Data Embedding for DFT-Based Image Steganography

As sharing digital media is getting more prominent, there has been a rise in the development of techniques for protecting digital media against misuse. However, the amount of such techniques has been less prominent for printed goods. The data hiding method presented in this paper is suited for the print domain. The method uses the Discrete Fourier Transform to embed data into images and Gray Component Replacement to maintain high image quality by masking embedding artifacts. This research examines whether the method's performance can be optimized using low-frequency ranges for embedding. The aim is to evaluate the usage of low-frequency ranges in order to achieve higher robustness. Different...

Effect of grey component replacement processing and varnishing on the light fastness of colours on cardboard prints

The visual appearance of packaging is one of its most important features. Electromagnetic irradiation causes a change in colour and often leads to colour fading (ie, to diminished visual appearance of a printed product). This research study aimed to determine the combined effect of grey component replacement image processing and varnishing on the protection of prints' appearance when exposed to accelerated ageing....

Robust DFT watermarking method with gray component replacement masking

The demand for security of shared digital and printed images is increasing year after year. There is a need for a robust watermarking scheme capable of offering high detection rates for very aggressive attacks, such as a print-scan process. However, high robustness of the watermark method usually leads to perceptible visual artifacts. Therefore, in this paper, a novel DFT watermarking method with gray component replacement (GCR) masking is proposed....

Modulation of water based commercial varnish by adding ZnO and SO2 nanoparticles to enhance protective function on printed packaging

The packaging sector of graphic industry is continuosly growing and developing in terms of packaging function used materials and production technology. The aim of this paper was to evaluate modification of commercial water-based varnish by determining its protective properties regarding colour degradation as well as barrier properties. For that purpose a set of composite coatings of different composition was prepared and applied onto cardboard prints. The prepared samples were characterized by measuring CIE L *a*b*􀀁 colour density and water vapour transfer rate before and after accelerated ageing. Results showed that applying prepared nanocomposite coatings do not cause significant colour...

ANTIMICROBIAL PROPERTIES OF TiO2 NANOCOMPOSITE COATING

Packaging plays important part of the visual communication and in consumer’s choice of purchasing goods. To enhance visual appearance, packaging material is often coated. Beside enhancement of visual appearance, additional coating often improves other packaging properties. The COVID-19 pandemic stressed the importance of the antimicrobial properties of goods that encounter consumers. During purchasing, consumer first meets the packaging making it significant in the consumer’s protection. The aim of this research is to determine antimicrobial properties of nanocomposite coating which includes nanosized TiO2. For the purpose of the research a set of offset cardboard prints was coated with ...

Lightfastness, surface and interfacial properties of colour-printed paper substrates coated with PCL/ZnO and PCL/TiO2 nanocomposites

Packaging production often includes varnishing to increase printed information durability. In addition, as some materials cannot be recycled (which could be the case in food packaging), the use of biobased materials enables waste to be composted. This paper proposes biopolymer-based nanocomposite coating which could be applied onto the printed paper substrate to protect it and increase its barrier properties to the water vapour. For the purpose of the research, two sets of the nanocomposite coatings were prepared by mixing polycaprolactone (PCL) base with ZnO or TiO2 nanoparticles in different weight concentrations. The prepared nanocomposites were applied onto the printed samples and artifi...

Color reproduction on varnished cardboard packaging by using lower ink coverages due to the gray component replacement image processing

Even in these challenging times, cardboard packaging industry is increasing its revenue with stable annual increase prediction, but customers are increasing demands on the packaging with respect to environmental protection, attractiveness, and branding. This article aims to determine the influence of image processing in terms of gray component replacement and overprint varnishing on the color reproduction on a cardboard packaging material. A test chart with tertiary colors was defined and modified by different gray component replacement levels. It was printed in accordance with ISO norm on coated and uncoated cardboard and finished by overprinting water based, offset, and UV varnish. The pre...

PCL-TIO2 Nanocomposite to Improve Ageing of Offset Prints

UV radiation or sunlight can affectthe printed sample by fading the ink surface and therefore the product losses it's decorative purpose and becomes less desirable to the customer. To create the efficient protective coating,titaniumdioxide(TiO2)will be used as a well-knowncompound that should lower the effects of UV radiation. TiO2should lower the colour fade after UV radiation and this will be determined by densitometric and colorimetric (CIE L*a*b*)measurements. In addition, measurement of print gloss will also be conducted to evaluate visual appearance of the sample. Biopolymer Polycaprolactone (PCL) wast...

Effect of the paper surface properties on the ink transfer parameters in offset printing

Paper has a crucial impact on the qualitative properties of printed product as properties of the paper’s surface directly impact the ink transfer, consequently, basic optical properties of the print. Although same ISO paper type, papers possess variable surface properties leading to different influence on the ink transfer. The aim of this research was to analyse influence of the surface properties of the paper, including surface free energy, smoothness and gloss of some standard papers used in lithography on the ink transfer while matching the colorimetric values defined by ISO 12647-2:2013. Determination of amount of the ink transfer, optical density, mottling and colour difference of pri...

The Influence of PCL-ZNO Coating Composition on Coated Offset Cardboard Prints

The most significant printing branch in these days is packaging printing. Packaging must primarily preserve the product from damaging, but at the same time must attract the consumers to be picked up from the shelf in the store. To ensure protective and aesthetic role of the packaging the prints are commonly coated with varnishes which will improve visual, mechanical, surface, and optical properties. In this paper a coating composed of polycaprolactone (PCL) and nanoscale ZnO was used to coat the offset prints on the cardboard. The coatings were prepared by adding various weight amounts of the ZnO nanoparticles (weight ratios of 0.1, 0.5 and 1%) into the mixture of PCL and ethyl-acetate. The ...

Adjustable color transformation model

Color management is an important part of the print production process. This paper presents a color transformation model which can provide all possible four-color solutions (CMYK) for a given aimed color (CIE L*a*b*). The model also allows quick adjustments of gamut mapping and total ink limit (TIL). The tests showed that the presented model is quite accurate. The model is less accurate for colors near the gamut boundary, but there is potential for improvements. Very high accuracy was achieved by avoiding gamut boundary colors. In practice, this is useful for application to image re-separation, usually with the aim of ink saving....

Analysis of the GCR Communication Channel For Image Steganography

Main motivation behind this investigation is to determine how and to what extend Gray Component Replacement (GCR) influences a color image. Specifically how GCR influences images in spatial domain, as well as in Fourier and Cosine domains. This is important to determine in order to develop a data hiding technique that can be used in GCR communication channel. To evaluate the influence of GCR on color images a large dataset is first converted from RGB to CMYK color space with very aggressive GCR. Then the original and the converted images are compared in Fourier and Cosine domains. The results show that the GCR communication channel has a nonlinear impact on the image that depends exclusively...

Sources of errors between color transforms

Characterization of output color reproduction devices has the purpose of ensuring accurate color reproduction. In the characterization process, two transforms are required: from device dependent colorant space to device independent color space, and in reverse direction. This paper identifies the sources of discrepancies between forward and reverse characterization models and investigates possibilities of their improvement. It is shown that lookup tables such as those used in ICC profiles inherently introduce errors near process boundaries. Partial improvements are possible by populating tables with proper values in critical regions....

Analysis of the interactions In the “varnish – photopolymer” system

Varnishing of the printed product is often carried out by means of a photopolymer flexographic printing plate. Various types of varnishes interacting with a photopolymer material can cause chemical changes in its surface layer and affect the acceptance and transfer of varnish to the print. The aim of this paper is to describe the interactions of different types of varnishes and standard styrene-isoprene-styrene flexographic printing plate and to analyse the influence of varnishes on the surface layer of the photopolymer material. Types of varnishes used in this research are matt and gloss water-dispersive varnish, oil-based and UV varnish. Their interactions with the printing plate were anal...

LS fitting of the material properties influencing the print quality in flexographic reproduction system

Printing quality is influenced by numerous parameters and by the material interactions in the ink- plate-substrate system. The aim of this paper is to characterize and quantify influential parameters in the flexographic reproduction system by using the method of the least squares (LS fitting). Specifically, this paper deals with influential properties of the printing plates and porous printing substrates (paper, board). Printing plate with its properties and interaction with the printing ink and substrate during the printing process affects the parameters of the print. Different properties of analysed porous substrates define properties of the print such as tonal values/dot gain and optical ...

Influence of the ink and substrate properties on the ink transfer in lithography

There are many parameters influencing transfer of the printing ink onto the printing substrates. Beside printing press characteristic one of most influential parameters is interface interactions in the offset blanket-printing ink-printing substrate system. The aim of this paper is to determine printing ink and substrate properties as an influential parameter to the printing ink transfer, i.e. properties of the imprint. To achieve this goal, this research will be conducted in three steps. First, characterization of the printing substrates (coated and uncoated samples) and printing ink will be performed. The printing substrates will be characterized by determining smoothness of paper accordi...

Applicability of TensorFlow environment in colorimetric analysis

TensorFlow environment gained a lot of momentum in recent years due to the increasing need for a fast, flexible and open source solution for a high performance numerical computation. Developed by Google Brain team, TensorFlow supports machine and deep learning across different industries. In this paper, TensorFlow is tested using colorimetric data and compared with an proprietary solutions for machine learning. The results show that TensorFlow is an able tool when it comes to the analysis of colorimetric data, and represents viable option as a free and open source solution which is relatively simple to employ with the use of TFLearn library....
Izvori
Stavka Opis
GCR - Python GitHub repozitorij
Image Attacks GitHub repozitorij
GCR Model Kod, testne slike, rezultati
GCR / DFT Model CodeOcean repozitorij
Kontakt

    M.E.G.A Project

    University of Zagreb, Facluty of Graphic Arts
    +385 1 2371 080 
    mega@grf.hr