Double Separation Method for Translation of the Infrared Information into a Visible Area


  • Ivana Žiljak Faculty of Graphic Arts, University of Zagreb
  • Klaudio Pap Faculty of Graphic Arts, University of Zagreb
  • Vilko Žiljak Faculty of Graphic Arts, University of Zagreb


Security Graphics, Infrared Colours, Colour Separation


Information visualization refers to the wavelength area ranging from 400 to 700 nm. Areas in lower wavelengths ranging from 100 to 400 nm are translated into the visual area with the goal to protect information visible only by applying instruments adapted for the ultraviolet area. Our recent research work refers to the infrared wavelength areas above the visible specter up to 1000 nm. The scientific contribution of this paper is in setting the double separation method for printing with CMYK printing inks with the goal to detect graphic information in the infrared area only. An algorithm has been created for making visual basics in the overall visible specter containing material that responds in the infrared section. This allows planning of areas in all coloring types for one and the same document that contains a secure piece of information. The system is based on double transition transformation of the visible RGB1 information recognition into CMYK2 in the same document. Secure information is recognized with the help of instruments in the set wavelength range. Most of the experiments have been carried out by analyzing the same set of RGB records. Each sample in the set was a test unit coming from another source containing different IR3 components. Thus an innovative method of color mixing has been set where colors appear respectively in daylight and separately according to IR light programming. New IR cryptography is proposed as shown in the experimental work.

Author Biographies

Ivana Žiljak, Faculty of Graphic Arts, University of Zagreb

Ph.D.Sc.Ivana Žiljak is a scientific recruit and assistant with the Zagreb University Faculty of Graphics in Zagreb. She was born in 1978 in Zagreb. In 2001 she graduated Design, College of Architecture. Since 2001 she has been a scientific recruit with the Faculty of graphics in Zagreb where she participates in teaching. In 2002 she enrolled for her doctor’s degree ‘Graphic engineering and graphic design’. In 2005 she got her Master of Science Degree with the Faculty of Graphics on basis of her paper entitled Document graphics with spot inks from the ultraviolet area, her mentor being D. Sc. Darko Agić. She passed her doctor’s degree in 2007.  with the Faculty of Graphics on basis of her paper entitled Designing security graphics with changing colours for digital printing in visible and invisible part of spectrum, her mentor being D. Sc. Darko Agić. Her specific field of work is theoretical and executive improving of design and printing with security protection against counterfeiting by using UV and IR inks, micro-lens, and holography. As a Research Fellow and young scientist she participates in two scientific projects with The Ministry of Science, Sports and Technology. 35 of her scientific and expert works have been published ( ). She has given lectures at 20 international congresses. She has exhibited at 6 independent exhibitions. She has participated in 17 selected design exhibitions in Croatia and abroad, and has won prizes. She passed the exam for a pilot license with the Ministry of Maritime, Traffic and Communications in 1997. She was in selecting committees at international design exhibitions, and she is the co-founder of the Croatian Design Center. She is a regular member of  Croatian Designer’s Society and of Art Directors Club in New York.

Klaudio Pap, Faculty of Graphic Arts, University of Zagreb

Ph.D.Sc.Klaudio Pap is assistant professor on the Faculty of Graphic Arts for course Computer Typography, Computer graphics and Computer programming. He is also lecturer for Design Studies courses Computer reprophotography  I. and II. and Computer Typography. He also gives lectures at the Polytehnic of Zagreb on the following: Web Search and Navigation, Web Interactive Programming, Graphic software Languages and Digital Printing. He was born on March 20, 1963, in Zagreb. During his work he has been engaged in research and development in areas of computer graphics, image and text processing, modeling and simulation with computers, web technologies, digital printing and graphics software languages. He is the co-writer of two books and he has published more then 30 scientific articles. He is the co-author of five development products and six software packages. He has taken an active part in six (8) research projects, and he was at the head of three of them. Since February 26, 2005 he has been a associate member of the Croatian Technical Science Academy.

Vilko Žiljak, Faculty of Graphic Arts, University of Zagreb

Ph.D.Sc.Vilko Žiljak is a full professor with permanent title in the field of graphic technology. He is a regular member of the Croatian Technical Sciences Academy. In 2008 he was awarded the life achievement award: Zlatna kuna (Gold Marten) for an exceptional contribution to the graphics industry development. He introduced new digitalization methods into the graphic industry in all segments: prepress, press and postpress. Software was introduced in printing plants for production managing and planning that he had developed with his closest collaborators. Significant projects are the following ones: digitalization of the state topographic maps, documents and securities graphics, design of Croatia's original money – the Kuna.




How to Cite

I. Žiljak, K. Pap, and V. Žiljak, “Double Separation Method for Translation of the Infrared Information into a Visible Area”, J. inf. organ. sci. (Online), vol. 33, no. 1, May 2009.