Restauração cromática digital de fotografias em filme a partir da cartela Kodak Q-13: estudo de caso do acervo do Projeto Portinari

Abstract

Photographic documentation of cultural property has been used since its inception in the early nineteenth century, through processes of chemical basis, being initially monochrome and color since the early twentieth century, now coming to the processes of electronic basis. With the aim of getting from the picture as much chromatic and tone information similar to the original object, the use of reference color targets with the scene/object has been adopted, whose function is to allow adjustments after the photographic record. These cards canalso collaborate in the identification of fading, in other words, chromatic loss to which color photographs of chemical basis are subject. In the photographic documentation of the works of the artist Portinari, held by the Portinari Project, object of this research study, conducted in the 1970s and 1980s, the Kodak Q- 13 reference color targets were used, color separation guide and gray scale, produced by Kodak or another authorized company. These targets were at first developed to evaluate and correct chemical basis color photographs and not for digital processing. The main objective in this research is a methodologydevelopment that can restore the colors and tones of photography through digital image processing, which Kodak Q-13 are the reference color targets. For this purpose it was made the colorimetric study of three different years of manufacturing of color and gray scale targets, and used two different colorimetric equipments to guarantee the generated color values. Results indicate better color matching consistency for the gray scale target than the color one. Results obtained from the experiments and developed methodologies show that it is possible to accomplish color restoration of the photographic images, which used Kodak Q-13 reference targets. Finally, restore and/or maintain photographic collections can collaborate with cultural heritage, and this collaboration can be in several ways: as a historical source, as a reference forrestores, authenticity identification, others.