Iván Marín-Franch

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Variations in illumination on a scene and trichromatic sampling by the eye limit inferences about scene content. The aim of this work was to elucidate these limits in relation to an ideal observer using color signals alone. Simulations were based on 50 hyperspectral images of natural scenes and daylight illuminants with correlated color temperatures 4000 K,(More)
The colors present in an image of a scene provide information about its constituent elements. But the amount of information depends on the imaging conditions and on how information is calculated. This work had two aims. The first was to derive explicitly estimators of the information available and the information retrieved from the color values at each(More)
The aim of this work was to investigate how efficiently colour information is distributed, in a least-redundancy sense, across the variables of a colour space, and how this distribution varies across different colour spaces. It was found that among the physiological and psychophysical colour spaces tested, Derrington-Krauskopf-Lennie space was the most(More)
The ability to perceptually identify distinct surfaces in natural scenes by virtue of their color depends not only on the relative frequency of surface colors but also on the probabilistic nature of observer judgments. Previous methods of estimating the number of discriminable surface colors, whether based on theoretical color gamuts or recorded from real(More)
PURPOSE The aim of this study was to explore how different statistical methods may lead to inconsistent inferences about the association between structure and function in glaucoma. METHODS Two datasets from published studies were selected for their illustrative value. The first consisted of measurements of neuroretinal rim area in the superior-temporal(More)
Measurement of retinal nerve fiber layer (RNFL) thickness using optical coherence tomography (OCT) is commonly used in the detection and management of glaucoma. The Stratus OCT (Carl Zeiss Meditec, Inc., Dublin, CA) is widely used, but image acquisition is subject to artifacts, such as those caused by normal fixational eye movements, and this leads to(More)
Estimates were made of the efficiency with which color spaces code color information from images of natural scenes. Six spaces were tested, namely, CIE XYZ tristimulus space, and the spaces CIELUV, CIELAB, CIELAB and S-CIELAB after chromatic adaptation with CMCCAT2000, and the space CIECAM02. For each space, the information available and the information(More)
The information preserved in identifying surfaces solely by their color can be quantified by measures defined by Shannon, including capacity and mutual information. The aim of this study was (1) to determine whether the capacity of an additive Gaus-sian channel provides an asymptotic upper bound to mutual information estimated for natural scenes under(More)
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