Kompenzacija metamerije promjenama vrijednosti R, G I B kanala kod portretnih fotografija s točno definiranom pozadinom

Željko Bosančić1, Ivana Pavlović1, Mile Matijević1

zeljko.bosancic@grf.hr, ivana.pavlovic@grf.hr, mile.matijević@grf.hr
1Sveučilište u Zagrebu Grafički fakultet, Getaldićeva 2, Zagreb, Hrvatska

Sažetak

Portret je od početka fotografije do danas jedan od najčešćih fotografskih motiva. Kroz povijest, a i danas aktivno potiče razvoj fotografskih sustava i tehnika. Danas se fotografski portreti konzumiraju u različitim svjetlosnim uvjetima definiranim, uz ostalo, temperaturom svjetla, što bitno utječe na njihov doživljaj. Niz ispitivanja je pokazao kako čak i malene promjene vrijednosti (unutar 10%) R, G i B kanala (crveni, zeleni i plavi kanal) pri reprodukciji ljudske kože uvelike utječu na doživljaj portreta. Tako i promatranje u različitim uvjetima, također utječe na percepciju, odnosno poruku koju portretna fotografija prenosi. U ovom radu se ispituje mogućnost kompenzacije, tako nastalih metamerijskih promjena boja kože kod portretnih fotografija sa standardnom pozadinom, uz standardne izvore svjetla točno određenim promjenama R, G i B vrijednosti digitalnog zapisa fotografije.
Ključne riječi: portretna fotografija, RGB kanali, metamerija, izvori svjetla

Compensation of metamerism by changing RGB channels in portrait photography with a predefined background

Abstract

Since the beginning of photography portrait was on of the most frequent photographic motives. Throughout history but also today it encourages development of photographic systems and techniques. Photographic portraits are today consumed in various lighting conditions defined by the temperature of light which significantly affects the experience. A set of previous tests has shown that even a slight change in values (within 10%) of R, G, B channels (red, green and blue) in reproduction of skin colors affects the experience of a portrait. In such a way different lighting conditions can affect perception and the message of a portrait photography. This paper examines the possibility of compensation metameric changes of skin color in portrait photography with a standard background, standard light sources using specific changes in R, G, and B values of the digital photographic images.
Keywords: portrait photography, RGB channels, metamerism, light sources


Patrik Ervells latest collection is ironically titled “Software”ADIDAS ORIGINALS TUBULAR SHADOW. In the notes from the presentation, Ervell says he was interested in developing tension between nostalgia and sci-fi,NIKE ZOOM WINFLO 3 and even included 90s cyberpunk amongst his influences. Ervell developed this point of view by creating an imaginary software company called Idegen software systems. He then re-appropriated the company’AIR JORDAN XXXI MENs logo in several of the collection’s garments. Elsewhere,MBT TARIKI MEN mohair coats with oversized lapels made an appearance alongside mock neck tees,NIKE AIR JORDAN RETRO 5 police-inspired ribbed sweaters,MBT FORA GTX WOMEN flight bombers, and polyurethane leather coats. The setting was also suitably dystopian, and the resulting ambiance was something akin to if the creators of Deutschland 83 and Hackers met up and decided to create a collection… We mean that as a compliment.Yesterday afternoon,JORDAN CP3 IX MEN artist JR spent the day working on his latest collaborative piece with Daniel Arsham in Greenpoint,NIKE AIR MAX 90 Brooklyn,MBT KIMONDO GTX MEN NYC. Connecting the lines between art, architecture, dance and theater, Daniel Arsham has been known to subvert existing architectural structures in unconventional,NIKE CLASSIC CORTEZ NYLON playful ways; confusing and confounding the expectations of space and form. Source: Street Art News .