Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 76 for “"Human visual system"”.
-
Wavelet-based Image Compression Using Human Visual System Models
… evaluated. Moreover, the sensitivities of the human visual system (HVS) are often not incorporated into compression schemes. This paper develops new wavelet models of the HVS and illustrates their performance for various scalar wavelet and multiwavelet transforms. The performance is measured …
-
Invariance properties of the human visual system in one-shot learning
This work first characterizes human invariant recognition in one-shot learning. By using novel stimuli, we address the question whether invariance to transformation emerges from experience and memorization of templates or from the brain instantly computing invariant representation. Our …
-
Noise-Enhanced and Human Visual System-Driven Image Processing: Algorithms and Performance Limits
… based on stochastic resonance (SR) noise and human visual system (HVS) properties, where several novel frameworks and algorithms for object detection in images, image enhancement and image segmentation as well as the method to estimate the performance limit of image segmentation algorithms are …
-
The dynamics of invariant object and action recognition in the human visual system
Humans can quickly and effortlessly recognize objects, and people and their actions from complex visual inputs. Despite the ease with which the human brain solves this problem, the underlying computational steps have remained enigmatic. What makes object and action recognition challenging are …
-
An electrophysiological study of chromatic processing in the human visual system. Using visual evoked potentials and electroretinograms to study cortical and retinal contributions to human trichromatic vision.
… the retinal and cortical contributions to human trichromatic colour vision. Chromatic processing at the cortex level was examined using visual evoked potentials (VEPs). These responses were elicited by chromatic spot stimuli, which were manipulated in order to selectively activate the …
-
Perceptual refinement for hierarchical radiosity
… explores the use of a simple model of the human visual system to yield a performance improvement with hierarchical radiosity. Hierarchical radiosity is a physically based rendering algorithm and hence makes no attempt to optimize computation for human perception. We used a model of the edge …
-
Shape from Gradients. A psychophysical and computational study of the role complex illumination gradients, such as shading and mutual illumination, play in three-dimensional shape perception.
The human visual system gathers information about three-dimensional object shape from a wide range of sources. How effectively we can use these sources, and how they are combined to form a consistent and accurate percept of the 3D world is the focus of much research. In complex scenes …
-
Characterizing human vision through large-scale brain imaging and computational models
Efforts to understand the neural underpinnings of human visual processing require sufficient experimental data and robust models. This thesis significantly contributes to both these fronts while simultaneously elucidating some of the most intriguing aspects of the human visual system. In the first …
-
Investigating the Role of Biological Constraints in Adversarial Robustness via Modeling and Representational Geometry
… excellent performance and even outperform humans on various computer vision tasks, the robustness of DNNs to small perturbations is still far from being comparable to the human visual system. Indeed, adversarial attacks, which are very small worst-case perturbations, can reduce the accuracy …
-
Perception of Lighting and Reflectance in Real and Synthetic Stimuli
The human visual system estimates the proportion of light reflected off of a surface despite variable lighting in a scene, a phenomenon known as lightness constancy. Classically, lightness constancy has been explained as a 'discounting' of the lighting intensity (Helmholtz, 1866), and this …
-
Time will tell: Material surface cues for the visual perception of material ageing Insights from psychophysics, online experiments, image processing and a science festival
This thesis explores the visual perception of material change over time, a novel topic that has received little attention so far. We aimed to understand the material surface features and mental representations associated with material change over time by the human visual system, and possibly wider …
-
Perceptually inspired image estimation and enhancement
… and enhancement algorithms inspired by human vision. In the first part of the thesis, we propose an algorithm for mapping one image to another based on the statistics of a training set. Many vision problems can be cast as image mapping problems, such as, estimating reflectance from …
-
Development of video quality metrics based on psychovisual models of early vision
… and reduce storage space while preserving visual quality requires quality metrics that accurately describe how people perceive distortion. A severe problem for developing new video quality metrics is limited data on how the human visual system processes spatial and temporal information …
-
Learning coupled conditional random field for image decomposition : theory and application in object categorization
… goal of this thesis is to build a computational system that is able to identify object categories within images. To this end, this thesis proposes a computational model of "recognition-through-decomposition-and-fusion" based on the psychophysical theories of information dissociation and …
-
Assessment of anthropocentric representations of color patterns for biological relevance
… difficult task as animals differ in their visual system properties (number of cone cells, spectral sensitivities of cone cells, filtering properties of ocular media, etc.) and thus may perceive and respond to stimuli differently than we do. These observations have led some to propose that …
-
Understanding and predicting where people look in images
For many applications in graphics, design, and human computer interaction, it is essential to understand where humans look in a scene. This is a challenging task given that no one fully understands how the human visual system works. This thesis explores the way people look at different types of …
-
Path from Photorealism to Perceptual Realism
… be perceptually realistic, providing that it is visually indistinguishable to human eyes. Due to the limitations of human vision, a significant improvement in perceptual realism can, in principle, be achieved by fulfilling the essential visual requirements with sufficient qualities and without …
-
Image analysis using visual saliency with applications in hazmat sign detection and recognition
<p>Visual saliency is the perceptual process that makes attractive objects "stand out" from their surroundings in the low-level human visual system. Visual saliency has been modeled as a preprocessing step of the human visual system for selecting the important visual information from a scene. We …
Page 1 of 4