Results 1 - 10 of 4,718

Snakes: Active contour models

by Michael Kass, Andrew Witkin, Demetri Terzopoulos - INTERNATIONAL JOURNAL OF COMPUTER VISION , 1988
"... A snake is an energy-minimizing spline guided by external constraint forces and influenced by image forces that pull it toward features such as lines and edges. Snakes are active contour models: they lock onto nearby edges, localizing them accurately. Scale-space continuation can be used to enlarge ..."
Abstract - Cited by 3951 (17 self) - Add to MetaCart
the cap-ture region surrounding a feature. Snakes provide a unified account of a number of visual problems, in-cluding detection of edges, lines, and subjective contours; motion tracking; and stereo matching. We have used snakes successfully for interactive interpretation, in which user-imposed constraint

Excitatory and inhibitory interactions in localized populations of model

by Hugh R. Wilson, Jack D. Cowan - Biophysics , 1972
"... ABSMAcr Coupled nonlinear differential equations are derived for the dynamics of spatially localized populations containing both excitatory and inhibitory model neurons. Phase plane methods and numerical solutions are then used to investigate population responses to various types of stimuli. The res ..."
Abstract - Cited by 495 (11 self) - Add to MetaCart
ABSMAcr Coupled nonlinear differential equations are derived for the dynamics of spatially localized populations containing both excitatory and inhibitory model neurons. Phase plane methods and numerical solutions are then used to investigate population responses to various types of stimuli

Contour Detection and Hierarchical Image Segmentation

by Pablo Arbeláez, Michael Maire, Charless Fowlkes, Jitendra Malik - IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE , 2010
"... This paper investigates two fundamental problems in computer vision: contour detection and image segmentation. We present state-of-the-art algorithms for both of these tasks. Our contour detector combines multiple local cues into a globalization framework based on spectral clustering. Our segmentati ..."
Abstract - Cited by 389 (24 self) - Add to MetaCart
This paper investigates two fundamental problems in computer vision: contour detection and image segmentation. We present state-of-the-art algorithms for both of these tasks. Our contour detector combines multiple local cues into a globalization framework based on spectral clustering. Our

The Contour Spectrum

by Chandrajit Bajaj , Valerio Pascucci, Daniel R. Schikore , 1997
"... We introduce the contour spectrum, a user interface component that improves qualitative user interaction and provides real-time exact quantification in the visualization of isocontours. The contour spectrum is a signature consisting of a variety of scalar data and contour attributes, computed over t ..."
Abstract - Cited by 187 (33 self) - Add to MetaCart
We introduce the contour spectrum, a user interface component that improves qualitative user interaction and provides real-time exact quantification in the visualization of isocontours. The contour spectrum is a signature consisting of a variety of scalar data and contour attributes, computed over

Competition for consciousness among visual events: the Psychophysics of reentrant visual processes

by Vincent Di Lollo, James T. Enns, Ronald A. Rensink - Journal of Experimental Psychology: General , 2000
"... Advances in neuroscience implicate reentrant signaling as the predominant form of communication between brain areas. This principle was used in a series of masking experiments that defy explanation by feed-forward theories. The masking occurs when a brief display of target plus mask is continued wit ..."
Abstract - Cited by 184 (18 self) - Add to MetaCart
-forward views based on inhibitory contour interactions. From the time a stimulus first enters the eye to the time a percept emerges into consciousness, the initial stimulus has been coded at several levels in the visual system. One of the main goals in studying visual information processing is to specify

A Neural Model of Contour Integration in the Primary Visual Cortex

by Zhaoping Li - Neural Computation , 1998
"... Experimental observations suggest that contour integration may take place in V1. However, there has yet to be a model of contour integration that only uses known V1 elements, operations, and connection patterns. This paper introduces such a model, using orientation selective cells, local cortical ci ..."
Abstract - Cited by 124 (5 self) - Add to MetaCart
circuits, and horizontal intra-cortical connections. The model is composed of recurrently connected excitatory neurons and inhibitory interneurons, receiving visual input via oriented receptive fields resembling those found in primary visual cortex. Intracortical interactions modify initial activity

Analysis and Synthesis of Facial Image Sequences Using Physical and Anatomical Models

by Demetri Terzopoulos, Keith Waters - IEEE Transactions on Pattern Analysis and Machine Intelligence , 1993
"... We present a new approach to the analysis of dynamic facial images for the purposes of estimating and resynthesizing dynamic facial expressions. The approach exploits a sophisticated generatire model of the human face originally developed for realistic facial animation. The face model, which may be ..."
Abstract - Cited by 228 (5 self) - Add to MetaCart
be simulated and rendered at interactive rates on a graphics workstation, incorporates a physics-based synthetic facial tissue and a set of anatomically motivated facial muscle actuators. We consider the estimation of dynamic facial muscle contractions from video sequences of expressive human faces. We develop

Effects of Tone and Focus on the Formation and Alignment of F0 Contours

by Yi Xu , 1999
"... The present study examines how lexical tone and focus contribute to the formation and alignment of f0contours in speech. This was done through an investigation of f0contour formation in short Mandarin sentences. These sentences all consisted of five syllables with varying tones on the middle three s ..."
Abstract - Cited by 148 (50 self) - Add to MetaCart
, the f0contour of a tone remains closely aligned with the associated syllable; and (d) both focus and tonal interaction may generate substantial f0decline over the course of an utterance. These findings seem to be able to reduce the unpredictability in the formation and alignment of f0contours in speech.

Extraction of Perceptually Salient Contours by Striate Cortical Networks

by Shih-cheng Yen, Leif H. Finkel , 1998
"... We present a cortical-based model for computing the perceptual salience of contours embedded in noisy images. It has been suggested (Gilbert, 1992; Field, Hayes & Hess, 1993) that horizontal intra-cortical connections in primary visual cortex may modulate contrast detection thresholds and pre-at ..."
Abstract - Cited by 69 (4 self) - Add to MetaCart
-attentive "popout ". In our model, horizontal connections mediate context-dependent facilitatory and inhibitory interactions among oriented cells. Strongly facilitated cells undergo temporal synchronization; and perceptual salience is determined by the level of synchronized activity. The model accounts

Distributed Memory and the Representation of General and Specific Information

by James L. McClelland, David E. Rumelhart , 1985
"... We describe a distributed model of information processing and memory and apply it to the representation of general and specific information. The model consists of a large number of simple processing elements which send excitatory and inhibitory signals to each other via modifiable connections. Infor ..."
Abstract - Cited by 188 (13 self) - Add to MetaCart
. Information processing is thought of as the process whereby patterns of activation are formed over the units in the model through their excitatory and inhibitory interactions. The memory trace of a processing event is the change or increment to the strengths of the interconnections that results from
Results 1 - 10 of 4,718