Cviljušac, Vladimir (2020) Razvoj sustava rekonstrukcije tiskanih računalno generiranih holograma = Development of printed computer generated holograms reconstructing system. Dissertation (PhD) thesis. Grafički fakultet. [Mentor: Mrvac, Nikola].
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Abstract
Multimedijski informacijski sustavi temelje se na tehnološkom razvoju računala u svrhu obrade, prijenosa i integracije svih vrsta informacija. Unaprjeđenje računalnih komponenti, arhitektura i metoda u posljednjih nekoliko godina omogućava razvoj novih pristupa i mnogo kompleksnijih algoritama u svrhu postizanja brže, sigurnije i višedimenzionalne komunikacije. Tiskani računalno generirani hologram (CGH – Computer Generated Hologram) kao multimedijski element predstavlja značajan napredak u odnosu na klasičnu holografiju. U ovome radu prikazan je novi postupak ispisa standardnim grafičkim tehnologijama i determinirani su kriteriji optičke rekonstrukcije tiskanih računalno generiranih holograma. Ispis računalno generiranih holograma zahtjeva specifičnu pripremu za tisak koja je ovisna o vrsti korištene grafičke tehnike, što se manifestira na pretvorbi digitalne veličine (piksel) u odgovarajuću fizičku veličinu za korišteni standardni proces ispisa. Veliki nedostatak je nepostojanje specijaliziranih programskih alata namijenjenih računalnom generiranju holograma te njihov iznimno zahtjevan izračun. Za potrebe disertacije napravljena je nova robusna metoda i pretvorena u računalni program koji omogućava povezivanje s komercijalnim 3D alatima (učitavanje točkastih 3D modela) te upravljanje simulacijom valne optike holograma putem grafičkog korisničkog sučelja. Time se zamijenio realni fizički objekt koji se upotrebljava u klasičnoj holografiji. U skladu s time napravljen je laboratorijski prototip za sigurnosnu analizu i provjeru autentičnosti isprintanih holograma. Predložena metoda također omogućuje brzu provjeru autentičnosti, bez potrebe za složenim optičkim postavom, korištenjem običnog točkastog LED (Light-Emitting Diode) svijetla. Definirani su kriteriji i parametri u ovisnosti o korištenoj grafičkoj tehnologiji koji moraju biti zadovoljeni za kvalitetan ispis i optičku rekonstrukciju tiskanih računalno generiranih holograma. Istraživanje se temeljilo na ispitivanju strojeva i tehnika ispisa, protokola, optičkom postavu, mjerenjima i sve je pretvoreno u jednu postojanu i upotrebljivu metodu koja može svaki isprintani računalno generiranih hologram učiniti jedinstvenim.
| Item Type: | Dissertation (PhD) thesis |
|---|---|
| Mentor name: | Mrvac, Nikola |
| Thesis Committee: | Pap, Klaudio and Modrić, Damir and Milković, Marin and Matijević, Mile and Radošević, Danijel |
| Defence date: | 3 September 2020 |
| Abstract in english: | Multimedia information systems are based on the technological development of computers for the purpose of processing, transmitting and integrating all types of information. The advancement of computer components, architecture, and methods over the last few years enables the development of new approaches and more complex algorithms to achieve faster, safer and multidimensional communication. The printed computer generated hologram as a multimedia element represents a significant advance compared to the classic holography. In this dissertation is presented a new printing process using standard graphics technology and determination of criteria for optical reconstruction of printed computer generated holograms. The printing process of computer generated holograms requires specific prepress that depends on the used type of printing technique, which is manifested on digital pixel size conversion to the appropriate physical size for the used type of standard print process. A major drawback is the lack of specialized software tools designed for hologram generation and their extremely demanding calculation. For research purposes, a computer program is developed that enables the linking with commercial 3D tools (using 3D Point Cloud Model as input object) and the controlling the wave optics simulation through a graphical user interface. That replaced the real physical object used in classical holography. A laboratory prototype is developed to define criteria and parameters depending on the used graphics technology, which must be met in order to obtain high quality printing and optical reconstruction of printed computer generated holograms. Proposed method also allows for a quick authentication with no need for a complex optical setup, while offering high-level security analysis through a simple yet robust system. Beyond computational method, research is based on testing machines and printing techniques, protocol, optical measuring setup and derived all-in-one highly defined conclusive usable method capable of making every CGH unique. Methodology For the purposes of the experiment and confirmation of the set hypotheses, system of creation and reconstruction of printed computer-generated holograms was developed. System consists of: method and program for computer-generated holograms, prepressprocess and laboratory prototype for optical reconstruction. It was necessary to develop a mathematical model of hologram calculation, which is based on one of the physical methods of holography. The final calculation result (binary martix) is converted into prepress in correlation with the capabilities of the selected graphic printing technique. Due to various capabilities of certain graphic printing techniques, it was necessary to develop a computer program that will, with the help of a graphical user interface, enable management of physical parameters of calculations. The system provides the rapid production of large amount of holograms. Main results The dissertation presents the results of proposed method of generating and reconstructing printed computer - generated holograms and the influence of capabilities of the printing techniques used in the production process. The research showed that the set goals and hypotheses are justified and proven. This dissertation provides an original scientific contribution that is manifested in the development of a new method of printing computergenerated holograms using standard graphic printing techniques. For this purpose original computer program for controlling calculation variables has been developed and the process of creating computer - generated hologram prepress has been defined. A laboratory prototype for optical reconstruction and authentication has been developed and used to define criteria for quality optical reconstruction and authentication keys for the protection of printed computer-generated holograms used in security printing. With the results of the research, system offers two main advantages: (a) fast and cheap production of holograms using commercial printing techniques and materials (making holograms applicable in small and large editions when needed), (b) simple and intuitive computer program with a graphical user interface that provides customization and control of calculation process for printing. This enables its wide application. |
| Uncontrolled Keywords: | računalno generiranih hologram, tisak, 3D točkasti model, optička rekonstrukcija, zaštitni tisak |
| Keywords in english: | computer generated hologram, print, 3D point cloud model, optical reconstruction, security print |
| Subjects: | TECHNICAL SCIENCES > Graphic Technology |
| Institution: | Grafički fakultet |
| City: | Zagreb |
| Number of Pages: | 144 |
| Callnumber: | 655:778.38:004 CVI r |
| Inventory number: | 10345 |
| Depositing User: | Nina Jelača |
| Status: | Unpublished |
| Date Deposited: | 08 Sep 2020 11:05 |
| Last Modified: | 03 Feb 2021 10:26 |
| URI: | http://eprints.grf.unizg.hr/id/eprint/3167 |
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