Author: Eunice Jingmei Tan
Publisher: Frontiers Media SA
ISBN: 283251832X
Category : Science
Languages : en
Pages : 128

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Book Description

Author: Eyal Izhak Nitzany
Publisher:
ISBN:
Category :
Languages : en
Pages : 276

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Book Description
Extraction of local motion signals is crucial for our survival. Lack of information from local motion signals will significantly reduce our ability to discriminate objects from background, avoid obstacles, and navigate. Despite the apparent effortlessness with which we perceive visual motion, there are indications that the underlying neural computations are complex. Three kinds of local motion signals have been distinguished, based on the kinds of spatiotemporal correlations that generate them: Fourier (F), based on 2-point correlations [1]; non-Fourier (NF), based on 4-point correlations [2]; and glider (G), based on 3-point correlations [3]. G signals have two subtypes, expansion and contraction, associated with objects that are looming and receding, respectively. Detection of isolated G and NF signals cannot be mediated by a purely multiplicative cross-correlator or a purely quadratic motion energy model. G signals have recently attracted substantial attention, following the demonstration that a wide range of species (human [3], macaque [4, 5], zebrafish [6], dragonfly [5], and fruitfly [7]) respond to them in similar ways suggesting that there are advantages to using these signals in visual tasks. This work expands the above lines of research in several respects. First, our computational work shows that these motion signals appear in natural scenes and characterizes the basic statistical relationships between them [8]. Second, we report neurophysiological recordings in two distinct visual-speciaist species (macaques and dragonflies) that demonstrate that at the neuronal level, cells response in a similar manner to motion signals in many respects, although there are subtle differences in responses between the species. This convergence at the algorithmic and neural-implementation levels indicate the fundamental biological importance of using the many kinds of motion signals to guide behavior. Finally, we carried out a psychophysical experiment to probe human ability to use multiple kinds of local motion signals simultaneously to solve simple directional task. We found that humans can combine different kinds of motion signals to solve this task, and, interestingly, that sensitivity to different kinds of motion signals is context-dependent.

Author: Albert James Myer
Publisher:
ISBN:
Category : Signals and signaling
Languages : en
Pages : 484

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Book Description

Author: Donald Patrick Gallogly
Publisher:
ISBN:
Category : Motion perception (Vision)
Languages : en
Pages : 140

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Book Description

Author: Mrinal Kr. Mandal
Publisher: Springer Science & Business Media
ISBN: 1461502659
Category : Computers
Languages : en
Pages : 383

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Book Description
Multimedia Signals and Systems is primarily a technical introductory level multimedia textbook, including problems, examples, and MATLAB® codes. It will be a stepping-stone for readers who want to research in audio processing, image and video processing, and data compression. This book will also be useful to readers who are carrying out research and development in systems areas such as television engineering and storage media. Anyone who seeks to learn the core multimedia signal processing techniques and systems will need Multimedia Signals and Systems. There are many chapters that are generic in nature and provide key concepts of multimedia systems to technical as well as non-technical persons. There are also several chapters that provide a mathematical/ analytical framework for basic multimedia signal processing. The readers are expected to have some prior knowledge about discrete signals and systems, such as Fourier transform and digital filters. However, a brief review of these theories is provided. Additional material for this book, including several MATLAB® codes along with a few test data samples; e.g., audio, image and video may be downloaded from http://extras.springer.com.

Author: Albert James Myer
Publisher:
ISBN:
Category : Communication
Languages : en
Pages : 668

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Book Description
A manual of signals so that members of the military can communicate with each other.

Author: Intergovernmental Maritime Consultative Organization
Publisher:
ISBN:
Category : Merchant marine
Languages : en
Pages : 172

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Book Description

Author: Great Britain. Board of Trade
Publisher:
ISBN:
Category : Merchant marine
Languages : en
Pages : 374

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Book Description

Author: Jeanny Herault
Publisher: World Scientific Publishing Company
ISBN: 9813107545
Category : Computers
Languages : en
Pages : 308

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Book Description
At the fascinating frontiers of neurobiology, mathematics and psychophysics, this book addresses the problem of human and computer vision on the basis of cognitive modeling. After recalling the physics of light and its transformation through media and optics, Hérault presents the principles of the primate's visual system in terms of anatomy and functionality. Then, the neuronal circuitry of the retina is analyzed in terms of spatio-temporal filtering. This basic model is extended to the concept of neuromorphic circuits for motion processing and to the processing of color in the retina. For more in-depth studies, the adaptive non-linear properties of the photoreceptors and of ganglion cells are addressed, exhibiting all the power of the retinal pre-processing of images as a system of information cleaning suitable for further cortical processing. As a target of retinal information, the primary visual area is presented as a bank of filters able to extract valuable descriptors of images, suitable for categorization and recognition and also for local information extraction such as saliency and perspective. All along the book, many comparisons between the models and human perception are discussed as well as detailed applications to computer vision./a

Author: Anna Esposito
Publisher: Springer Science & Business Media
ISBN: 3642005241
Category : Computers
Languages : en
Pages : 362

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Book Description
This book constitutes the thoroughly refereed post-conference proceedings of the COST Action 2102 and euCognition supported international school on Multimodal Signals: "Cognitive and Algorithmic Issues" held in Vietri sul Mare, Italy, in April 2008. The 34 revised full papers presented were carefully reviewed and selected from participants’ contributions and invited lectures given at the workshop. The volume is organized in two parts; the first on Interactive and Unsupervised Multimodal Systems contains 14 papers. The papers deal with the theoretical and computational issue of defining algorithms, programming languages, and determinist models to recognize and synthesize multimodal signals. These are facial and vocal expressions of emotions, tones of voice, gestures, eye contact, spatial arrangements, patterns of touch, expressive movements, writing patterns, and cultural differences, in anticipation of the implementation of intelligent avatars and interactive dialogue systems that could be exploited to improve user access to future telecommunication services. The second part of the volume, on Verbal and Nonverbal Communication Signals, presents 20 original studies devoted to the modeling of timing synchronisation between speech production, gestures, facial and head movements in human communicative expressions and on their mutual contribution for an effective communication.