caa a22 4500 467914222 CHVBK 20180406152857.0 cr unu---uuuuu 170328e20060801xx s 000 0 eng 10.1007/s11263-006-6858-4 doi (NATIONALLICENCE)springer-10.1007/s11263-006-6858-4 Visual Acuity in Day for Night [Elektronische Daten] [Gloria Haro, Marcelo Bertalmío, Vicent Caselles] In film production, it is sometimes not convenient or directly impossible to shoot some night scenes at night. The film budget, schedule or location may not allow it. In these cases, the scenes are shot at daytime, and the ‘night look' is achieved by placing a blue filter in front of the lens and under-exposing the film. This technique, that the American film industry has used for many decades, is called ‘Day for Night' (or ‘American Night' in Europe.) But the images thus obtained don't usually look realistic: they tend to be too bluish, and the objects' brightness seems unnatural for night-light. In this article we introduce a digital Day for Night algorithm that achieves very realistic results. We use a set of very simple equations, based on real physical data and visual perception experimental data. To simulate the loss of visual acuity we introduce a novel diffusion Partial Differential Equation (PDE) which takes luminance into account and respects contrast, produces no ringing, is stable, very easy to implement and fast. The user only provides the original day image and the desired level of darkness of the result. The whole process from original day image to final night image is implemented in a few seconds, computations being mostly local. Springer Science + Business Media, LLC, 2006 day for night nationallicence visual perception nationallicence dark adaptation nationallicence non-linear diffusion nationallicence Haro Gloria Departament de Tecnologia, Universitat Pompeu Fabra, Barcelona, Spain aut Bertalmío Marcelo Departament de Tecnologia, Universitat Pompeu Fabra, Barcelona, Spain aut Caselles Vicent Departament de Tecnologia, Universitat Pompeu Fabra, Barcelona, Spain aut International Journal of Computer Vision Kluwer Academic Publishers 69/1(2006-08-01), 109-117 0920-5691 69:1<109 2006 69 11263 https://doi.org/10.1007/s11263-006-6858-4 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11263-006-6858-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Haro Gloria Departament de Tecnologia, Universitat Pompeu Fabra, Barcelona, Spain aut NATIONALLICENCE 700 1- Bertalmío Marcelo Departament de Tecnologia, Universitat Pompeu Fabra, Barcelona, Spain aut NATIONALLICENCE 700 1- Caselles Vicent Departament de Tecnologia, Universitat Pompeu Fabra, Barcelona, Spain aut NATIONALLICENCE 773 0- International Journal of Computer Vision Kluwer Academic Publishers 69/1(2006-08-01), 109-117 0920-5691 69:1<109 2006 69 11263 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer