오토 화이트밸런스와 커스텀 화이트밸런스 설정에 따른 이미지 재현성에 관한 비교 연구

Abstract

This study aims at offering some theoretical foundations and at helping choose the proper white balance setting, by comparing and analyzing the characteristics of the automatic white balance setting, with which digital cameras and RWA file converting programs are equipped, and the characteristics of the custom white balance setting, using a gray card, a white card, and etc. For this analysis, Kodak gray scale (large) Q-14, Kodak color control patches Q-14, Macbeth color checker, a Fotowand gray card, and a Fotowand white card were used, with automatic white balance setting and with custom white balance setting respectively, and also with the speed light of less color temperature changes. Also, the image reproducibility, such as the changes of image tone, color representation, chroma, noise density, and dynamic range, was analyzed through Photoshop CS3 and through Imatest-1.6.16. The analysis results showed that when the same algorism was applied to, it brought about various results, but some characteristics of each case and some minute comparative superiority of setting were found, while the products of one company had different features and it was difficult to find just one rule with one model. As for the color tone, generally, when a gray card was used and the coloration of neutral gray was reproduced nicely, the white color was represented with a warm feeling, and when a white card was used and the coloration of the white color was nice, the neutral gray was represented with a cold feeling. When a white card was set up, the error range of white balance was smallest, and therefore it would be much better to set up a white card to photograph a bright subject, in particular, such as a white background or an achromatic color. This study contributed to theorizing the mostly used settings through objective experiments, in spite of its limitation of the application of the same algorism.