52,101 research outputs found
Resenha de FAUSTINO, M.; RYAN, B.; FERRARO, G. (Org.). Rostos do Si: Autobiografia, Confissão, Terapia
No full textResenha do livro FAUSTINO, M.; RYAN, B.; FERRARO, G. (Org.). Rostos do Si: Autobiografia, Confissão, Terapia. Lisboa: Livros Vendaval, 2019. 359p
Il danno alla persona nelle specificità delle relazioni di lavoro: un'opinione controcorrente
No full textImage contrast enhancement via entropy production
No full textIn this paper a novel approach for image contrast enhancement is proposed. Employing a thermodynamical model to define local information content, the method derives a measure of local contrast which takes into account spatial structure across multiple scales. From this measure a local contrast map is computed, which is then applied to the image, giving rise to a selective enhancement of the original image. Here some applications to medical images will be presented as well as a comparison with other methods
Feed and fly control of visual scanpaths for foveation image processing
No full textFoveation-based processing and communication systems can exploit a more efficient representation of im- ages and videos by removing or reducing visual information redundancy, provided that the sequence of foveation points, the visual scanpath, can be determined.
However, one point that is neglected by the great ma- jority of foveation models is the ”noisy” variation of the random visual exploration exhibited by different observers when viewing the same scene, or even by the same sub- ject along different trials. Here a model for the generation and control of scanpaths that accounts for such issue is pre- sented. In the model, the sequence of fixations and gaze shifts is controlled by a saliency-based, information forag- ing mechanism implemented through a dynamical system switching between two states, ”Feed” and ”Fly”.
Results of the simulations are compared with experimental data derived from publicly available datasets
Gaze shift behavior on video as composite information foraging
No full textThe ability to predict, given an image or a video, where a human might fixate elements of a viewed scene has long been of interest in the vision community. However, one point that is not addressed by the great majority of computational models is the variability exhibited by different observers when viewing the same scene, or even by the same subject along different trials. Here we present a model of gaze shift behavior which is driven by a composite foraging strategy operating over a time varying visual landscape and accounts for such variability.
The system performs a deterministic walk if in a neighborhood of the current position of the gaze there exists a point of sufficiently high saliency; otherwise the search is driven by a Langevin equation whose random term is generated by an a-stable distribution.
Results of the simulations on complex videos from the publicly available University of South California CRCNS eye-1 dataset are compared with eye-tracking data and show that the model yields gaze shift motor behaviors that exhibits statistics similar to those exhibited by human observers
Ecological sampling of gaze shifts
No full textVisual attention guides our gaze to relevant parts of the viewed scene, yet the moment-to-moment relocation of gaze can be different among observers even though the same locations are taken into account. Surprisingly, the variability of eye movements has been so far overlooked by the great majority of computational models of visual attention. In this paper we present the ecological sampling model, a stochastic model of eye guidance explaining such variability. The gaze shift mechanism is conceived as an active random sampling that the foraging eye carries out upon the visual landscape, under the constraints set by the observable features and the global complexity of the landscape. By drawing on results reported in the foraging literature, the actual gaze relocation is eventually driven by a stochastic differential equation whose noise source is sampled from a mixture of α-stable distributions. This way, the sampling strategy proposed here allows to mimic a fundamental property of the eye guidance mechanism: where we choose to look next at any given moment in time, it is not completely deterministic, but neither is it completely random To show that the model yields gaze shift motor behaviors that exhibit statistics similar to those displayed by human observers, we compare simulation outputs with those obtained from eye-tracked subjects while viewing complex dynamic scenes
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