TESTING COLOR APPEARANCE MODELS IN COMPLEX SCENE

The sensation of sight is our primary mechanism to perceive the world around us. However it is not yet perfectly clear how the human visual system works. The images of the world are formed on the retina, captured by sensors and converted in signals sent to the brain. Here the signals are processed and somehow interpreted, thus we are able to see. A lot of information, hypothesis, hints come from a field of the optical (or visual) illusions. These illusions have led many scientists and researchers to ask themselves why we are not able to interpret in a correct way some particular scenes. The word “interpret” underlines the fact that the brain, and not only the eye, is involved in the process of vision. If our sight worked as a measurement tool, similar to a spectrophotometer, we would not perceive, for example, the simultaneous contrast phenomenon, in which a grey patch placed on a black background appears lighter than an identical coloured patch on a white background. So, why do we perceive the patches as different, while the light that reaches the eyes is the same? In the same way we would not be able to distinguish a white paper seen in a room lit with a red light from a red paper seen under a white light, however humans can do this. These phenomena are called colour appearance phenomena. Simulating the appearance is the objective of a range of computational models called colour appearance models. In this dissertation themes about colour appearance models are addressed. Specific experiments, performed by human observers, aim to evaluate and measure the appearance. Different algorithms are tested in order to compare the results of the computational model with the human sensations about colours. From these data, a new printing pipeline is developed, able to simulate the appearance of advertising billboard in different context.