Color 3D Printing: Theory, Method, and Application

Our research team proposes a colored manufacturing technology with a layer-by-layer printing process. Using digital inkjet printing in layer-by-layer printing color graphics, a further low-cost color 3D Printing (3DP) technology can be developed. It can provide an integrated way to prototype and reproduce 3D objects, from concept to design and manufacturing. Ultimately, with fast graphics printing method, it guarantees a feasible way to further promote cultural and creative products

Optimizing Separation Parameters for Dedicated CMYKIR Reproduction Purposes With Hidden Double Information

Contemporary programming support for image correction and manipulation for graphic arts purposes implies partially regardless RGB/CMYK separation options, where particular parameters can be adjusted separately or by means of ICC profiles. As input image information can be reached from different dynamic range devices or can be generated, output reproduction devices can use various substrates and media, so additional adjustments and researches have to be carried out. CMYKIR reproduction has specific demands, while through the visual part of the spectrum (VS) colour management controls response and experience outside the visual, i.e. hidden information in the near infrared (NIR) domain, and claims to find dedicated adjustments for specificities of VS-CMYKIR reproduction

Evaluation of the press calibration methods by simulation

Press calibration is an approach to adjust the behavior of ink, paper, and press with the use of a CTP platemaking system to achieve a specified reference printing condition. Reference printing condition defines a common color space for color image data exchange between various output devices. The advantage of a reference printing condition is to improve color image quality and reduce cost and time. Corner points of the color gamut, TVI curves, and grey reproduction are the three significant elements in a reference printing condition, which make them essential in press calibration. There are usually two press runs in press calibration. The first press run (Run 1) is to adjust ink system of a press to achieve the color gamut conformance to the reference aims with linear plates. The second press run (Run 2) is to either adjust tonality or neutrality of the press with curved plates based on the Run 1 printing condition. Thus, the question is whether the two press calibration runs can meet the three requirements achieving full conformance according to the reference aims? This research assessed two cases starting with two real Run 1 printing conditions. In the both cases, ISO Type 1 paper was used and the color gamut was in conformance to the reference CGATS TR006 printing condition. Run 2 was a simulated calibration press run with the adjustment of either tonality or neutrality of the press. The use of A-to-B tag and B-to-A tag of the Run 1 ICC profile with absolute colorimetric rendering intent was the essential idea to simulate a calibrated Run 2 printing condition. The advantage is that no printing drafts would occur in the simulation approach, which guarantees repeatability from Run 1 to Run 2. The calibration results were verified to be in conformance first before other assessments. In other words, TVI curves of the TVI-based calibrated results were verified to be in conformance first before grey reproduction conformance was assessed; and grey reproduction of G7-based calibration results was verified to be in conformance first before TVI curves\u27 conformance was assessed. The research results show that (1) if deviations of TVI curves and grey reproduction in Run 1 printing conditions are close to the reference aims, either of the two calibration methods can achieve full conformance; and (2) if discrepancies of TVI curves and grey reproduction conformance in Run 1 printing conditions are far from the reference aims, a third requirement may not be in conformance unless adjustments will be iterated within specified tolerances

New Trends in 3D Printing

A quarter century period of the 3D printing technology development affords ground for speaking about new realities or the formation of a new technological system of digital manufacture and partnership. The up-to-date 3D printing is at the top of its own overrated expectations. So the development of scalable, high-speed methods of the material 3D printing aimed to increase the productivity and operating volume of the 3D printing machines requires new original decisions. It is necessary to study the 3D printing applicability for manufacturing of the materials with multilevel hierarchical functionality on nano-, micro- and meso-scales that can find applications for medical, aerospace and/or automotive industries. Some of the above-mentioned problems and new trends are considered in this book

Evaluation of the chromatic assimilation effect intensity in Munker-White samples produced using standard methods of rendering

U svakodnevnoj komunikaciji uobičajeno je da se određena valna duljina svjetlosti vidljivog spektra ili fizičkog objekta poistovjeti s njegovom bojom. Određivanje boje spada, kao fizikalni fenomen, u područje spektrofotometrije ili spektroradiometrije. Možemo reći da se određena valna duljina pod određenim uvjetima gledanja percipira kao njihova boja. Pojavnost boje neke slike koju promatramo uvjetovana je promjenom uvjeta gledanja. Takav fenomen predstavlja izazov komunikacijskim tehnologijama koje se za prijenos informacija služe informacijom o boji. Sustavi paralelnih linija različitog obojenja koji su svojim oblikom slični klasičnim Munker-White uzorcima upotrebljavaju se svakodnevno u različitim dizajnerskim rješenjima. Upotreba takovih sustava linija može uslijed manifestacije određenih psihofizikalnih vizualnih efekata uzrokovati potencijalno odstupanje u percepciji boje pojedinih elemenata. Zbog toga istraživanja u ovom radu usmjerena su na određivanje utjecaja pojedinih standardnih metoda renderiranja na magnitudu najintenzivnijeg efekta koji se manifestira kod različitih tipova Munker-White uzorka, odnosno efekta kromatske asimilacije.In everyday communication it is common that a particular wavelength of visible light spectrum or physical object is identified with its color. Determination of color as a physical phenomenon belongs to the area of spectrophotometry or spectrum-diometry. It can be said that, under certain conditions of viewing, a particular wavelength is perceived as their color. Occurrence of color of viewed pictures depends on the change of the viewing conditions. Such a phenomenon is a challenge to communication technologies which use information about the color for the transmission of information. Systems of parallel lines of various colors that with their shape are similar to the classic Munker-White samples are used daily in a variety of design solutions. The use of such line systems may potentially, due to the manifestation of certain psychophysical visual effects, cause deviation in color perception of individual elements. Therefore, the researches in this paper are focused on determining the impact of certain standard methods of rendering on the magnitude of the most intensive effect that is manifested in different types of Munker-White pattern, or the chromatic assimilation effect

Image-based Modeling 2-Dimension to 3-Dimension model

The objective of the report is to reflect the progress done in order to develop the final year project. This project main objective is to study the process of conversion of a two-dimensional image, in this case digital images into its corresponding three-dimensional image presentation and then come out with the solution to do so. The scope of the project will focus on a digital image of an object with smooth or even surface as the input for the application and as a result, the image will be converted into its corresponding three-dimensional image. The project also focused on having as a solution that enables the conversion of the images using the lowest cost possible, which preferable from the current tools available as they are quite expensive. The methodology used for the development of the project is a modified version of waterfall methodology. Some project activities are by doing more research to know in depth about two-dimensional image and also threedimensional image, using OpenGL in Visual Studio C++ environment framework. As a conclusion, the project is basically to build an image conversion system with a two-dimensional image as an inputto be converted into a three-dimensional image

THE INFLUENCE OF STANDARD RENDERING METHODS ON THE MANIFESTED INTENSITY OF THE CHROMATIC INDUCTION EFFECT

The focus of this work is directed to investigations with the aim of explaining the mutual relationships of parameters connected to the gamut size, rendering methods and the visual evaluations of the prints with the image presentations, which cause the psychophysical effect of the chromatic induction. The results of instrumental analysis in relation to the results of visual evaluation show aberration from the conventional point of view, according to which the increase of gamut size of prints is followed by the increase of the experience quality. In this sense the additional analyses are made and the correlations are determined which define the relationships of the previously mentioned parameters

Appearance-based image splitting for HDR display systems

High dynamic range displays that incorporate two optically-coupled image planes have recently been developed. This dual image plane design requires that a given HDR input image be split into two complementary standard dynamic range components that drive the coupled systems, therefore there existing image splitting issue. In this research, two types of HDR display systems (hardcopy and softcopy HDR display) are constructed to facilitate the study of HDR image splitting algorithm for building HDR displays. A new HDR image splitting algorithm which incorporates iCAM06 image appearance model is proposed, seeking to create displayed HDR images that can provide better image quality. The new algorithm has potential to improve image details perception, colorfulness and better gamut utilization. Finally, the performance of the new iCAM06-based HDR image splitting algorithm is evaluated and compared with widely spread luminance square root algorithm through psychophysical studies

Characterisation of Implant Supported Soft Tissue Prostheses Produced with 3D Colour Printing Technology

The numbers of patients needing facial prostheses has increased in the last few decades due to improving cancer survival rates. The many limitations of the handmade prostheses together with rapid expansion of prototyping in all directions, particularly in producing human anatomically accurate parts, have raised the question of how to employ this technology for rapid manufacturing of facial soft tissue prostheses. The idea started to grow and the project was implemented based on CAD/CAM principles – additive manufacturing technology, by employing layered fabrication of facial prostheses from starch powder and a water based binder and infiltrated with a silicone polymer (SPIS). The project aimed to produce a facial prosthesis by using 3D colour printing, which would match the patient’s skin shade and have the desirable mechanical properties, through a relatively low cost process that would be accessible to the global patient community. This was achieved by providing a simple system for data capture, design and reproducible method of manufacture with a clinically acceptable material. The prosthesis produced has several advantages and few limitations when compared to existing products/prostheses made from silicone polymer (SP). The mechanical properties and durability were not as good as those of the SP made prosthesis but they were acceptable, although the ideal properties have yet to be identified. Colour reproduction and colour matching were more than acceptable, although the colour of the SPIS parts was less stable than the SP colour under natural and accelerated weathering conditions. However, it is acknowledged that neither of the two methods used represent the natural life use on patients and the deficiencies demonstrated in terms of mechanical properties and colour instability were partially inherent in the methodology used, as the project was still at the developmental stage and it was not possible to apply real life tests on patients. Moreover, deficiencies in mechanical and optical properties were probably caused by the starch present, which was used as a scaffold for the SP. Furthermore, a suitable retention system utilising existing components was designed and added to the prosthesis. This enabled the prosthesis to be retained by implants with no need for the addition of adhesive. This would also help to prolong the durability and life span of the prosthesis. The capability of the printer to produce skin shades was determined and it was found that all the skin colours measured fall within the range of the 3D colour printer and thereby the printer was able to produce all the colours required. Biocompatibility was also acceptable, with a very low rate of toxicity. However, no material is 100% safe and each material has a certain range of toxicity at certain concentrations. At this stage of the project, it can be confirmed that facial prostheses were successfully manufactured by using 3D colour printing to match the patient’s skin shade, using biocompatible materials and having the desirable mechanical properties. Furthermore, the technology used enabled prostheses to be produced in a shorter time frame and at a lower cost than conventional SP prostheses. They are also very lightweight, easier to use and possibly more comfortable for the patients. Moreover, this technology has the capability of producing multiple prostheses at the time of manufacture at reduced extra cost, whilst the data can be saved and can be utilised/modified for producing further copies in the future without having to going through all the steps involved with handmade prostheses. Based on the mechanical properties and colour measurements the prostheses will have a finite service life and the recommendation is that these prostheses will need replacing every 6 to 12 months, depending on how the patient handles and maintains the prostheses and whether the prosthesis is being used as an interim or definitive prosthesis. This was largely comparable to existing prostheses but without the time and cost implications for replacement. However, it is acknowledged that further investigations and clinical case studies are required to investigate the “real life” effect on the prostheses and to get feedback from the patients in order to make appropriate improvements to the mechanical properties and the durability of the prosthesis