Search results for "processing"
showing 10 items of 8572 documents
GESTALT-INSPIRED FEATURES EXTRACTION FOR OBJECT CATEGORY RECOGNITION
2013
International audience; We propose a methodology inspired by Gestalt laws to ex- tract and combine features and we test it on the object cat- egory recognition problem. Gestalt is a psycho-visual the- ory of Perceptual Organization that aims to explain how vi- sual information is organized by our brain. We interpreted its laws of homogeneity and continuation in link with shape and color to devise new features beyond the classical proxim- ity and similarity laws. The shape of the object is analyzed based on its skeleton (good continuation) and as a measure of homogeneity, we propose self-similarity enclosed within shape computed at super-pixel level. Furthermore, we pro- pose a framework to …
Do categorical representations modulate early automatic visual processing? A visual mismatch-negativity study.
2021
Perceptual categorization is an important cognitive function. In the auditory domain, categorization already occurs within the first 200 ms of information processing, as indexed by the mismatch negativity. Here, we assessed the characteristics of the visual mismatch negativity (vMMN) elicited during the categorization of previously unknown visual stimuli. To examine this, we used five-dot patterns with characteristics that allow for the formation of categories through rotation and reflection but not through other physical properties. To assess whether or not between-category and within-category vMMN differ in amplitude, the data was analyzed with the Bayesian approach. We observed that both…
Multivariate EEG spectral analysis evidences the functional link between motor and visual cortex during integrative sensorimotor tasks
2012
The identification of the networks connecting brain areas and the understanding of their role in executing complex tasks is a crucial issue in cognitive neuroscience. In this study, specific visuomotor tasks were devised to reveal the functional network underlying the cooperation process between visual and motor regions. Electroencephalography (EEG) data were recorded from twelve healthy subjects during a combined visuomotor task, which integrated precise grip motor commands with sensory visual feedback (VM). This condition was compared with control tasks involving pure motor action (M), pure visual perception (V) and visuomotor performance without feedback (V + M). Multivariate parametric …
Image Content Enhancement Through Salient Regions Segmentation for People With Color Vision Deficiencies
2019
Color vision deficiencies affect visual perception of colors and, more generally, color images. Several sciences such as genetics, biology, medicine, and computer vision are involved in studying and analyzing vision deficiencies. As we know from visual saliency findings, human visual system tends to fix some specific points and regions of the image in the first seconds of observation summing up the most important and meaningful parts of the scene. In this article, we provide some studies about human visual system behavior differences between normal and color vision-deficient visual systems. We eye-tracked the human fixations in first 3 seconds of observation of color images to build real f…
Panel Summary: Plasticity and Reconfigurability in Sensory Systems
1997
Natural neural network are highly plastic in structure and function and may adapt to long lasting environmental changes. Plasticity and adaptation are not confined to lower level of processing, or to lower vertebrates, but also at the higher levels of visual processing in higher vertebrates are highly dynamic and perform considerable spatial integration. There are numerous influences that play a role in the functional architecture of the retina and the, cortex, the dynamics of the outside environment, the context within which a feature is presented, the history of previous visual stimulation and attention or expectation. The brief report on the visual system is integrated by the report of G…
Color stabilizes textbook visual processing
2011
We report that pages with color illustrations elicit more homogeneous duration of fixations in 12 elementary school children. For six first graders, we compared the reading of the color cover and a greyscale illustrated text page of an abcbook. For six second grade pupils, we demonstrated a color and a greyscale fairytale book page. The fixations we recorded are concordant with the duration for preschoolers reported elsewhere. Average duration of fixations on a page with color elements are shorter than on greyscale ones, 425 (SE=13.4) and 461 (18.3) ms, respectively. The correlation analysis lends support that a color page is processed differently than its greyscale version. Fixation durati…
Attention Direction in Static and Animated Diagrams
2010
Two key requirements for comprehending a diagram are to parse it into appropriate components and to establish relevant relationships between those components. These requirements can be particularly demanding when the diagram is complex and the viewers are novices in the depicted domain. Lack of domain-specific knowledge for top-down guidance of visual attention prejudices novices' extraction of task-relevant information. Static diagrams designed for novices often include visual cues intended to improve such information extraction. However, because current approaches to cueing tend to be largely intuitive, their effectiveness can be questionable. Further, animated diagrams with their percept…
Symmetry in Computer Vision
2002
Symmetry properties establish the invariance of a system to a given set of transformations. Physicists assign special meaning whenever symmetry is broken in nature; for example, groups of symmetry have been used to explain and predict the spatial organization of atoms in a crystal. Psychologists consider relevant the property of symmetry in the perception of visual signals. The paper will briefly describe different approaches, introduced in computer vision, to measure symmetry. A review of some applications at the Computer Vision Group (Department of Mathematics and Applications of Palermo University) is presented. They regard attentive visual processing, the analysis of faces, the recognit…
Do young readers have fast access to abstract lexical representations? Evidence from masked priming
2014
Although there is consensus that adult readers have fast access to abstract letter/word representations, the developmental trajectory of such access has not been mapped out yet. To examine whether developmental readers have rapid access to abstract representations during the early stages of word processing, we conducted a masked priming lexical decision experiment with two groups of young readers (third and fifth graders) and a group of young adults. We selected two types of words: (a) words composed of cross-case letters that are visually dissimilar (DIS words; e.g., arte/ARTE [Spanish for art]) and (b) words composed of cross-case letters that are visually similar (SIM words; e.g., vivo/V…
The effects of interletter spacing in visual-word recognition.
2010
Despite the importance of determining the effects of interletter spacing on visual-word recognition, this issue has often been neglected in the literature. The goal of the present study is to shed some light on this topic. The rationale is that a thin increase in interletter spacing, as in casino, may reduce lateral interference among internal letters without destroying a word's integrity and/or allow a more precise encoding of a word's letter positions. Here we examined whether identification times for word stimuli in a lexical decision task were faster when the target word had a slightly wider than default interletter spacing value relative to the default settings (e.g., casino vs. casino…