Neil D B Bruce | University of Manitoba (original) (raw)

Papers by Neil D B Bruce

In this paper we present a definition for visual saliency grounded in information theory. This pr... more In this paper we present a definition for visual saliency grounded in information theory. This proposal is shown to relate to a variety of classic research contributions in scale-space theory, interest point detection, bilateral filtering, and to existing models of visual saliency. Based on the proposed definition of visual saliency, we demonstrate results competitive with the state-of-the art for both prediction of human fixations, and segmentation of salient objects. We also characterize different properties of this model including robustness to image transformations, and extension to a wide range of other data types with 3D mesh models serving as an example. Finally, we relate this proposal more generally to the role of saliency computation in visual information processing and draw connections to putative mechanisms for saliency computation in human vision.

CVPR 2011 WORKSHOPS, 2011

Abstract The human brain uses visual attention to facilitate object recognition. Traditional theo... more Abstract The human brain uses visual attention to facilitate object recognition. Traditional theories and models envision this attentional mechanism either in a pure feedforward fashion for selection of regions of interest or in a top-down task-priming fashion. To these ...

PLOS ONE, 2015

Saliency maps produced by different algorithms are often evaluated by comparing output to fixated... more Saliency maps produced by different algorithms are often evaluated by comparing output to fixated image locations appearing in human eye tracking data. There are challenges in evaluation based on fixation data due to bias in the data. Properties of eye movement patterns that are independent of image content may limit the validity of evaluation results, including spatial bias in fixation data. To address this problem, we present modeling and evaluation results for data derived from different perceptual tasks related to the concept of saliency. We also present a novel approach to benchmarking to deal with some of the challenges posed by spatial bias. The results presented establish the value of alternatives to fixation data to drive improvement and development of models. We also demonstrate an approach to approximate the output of alternative perceptual tasks based on computational saliency and/or eye gaze data. As a whole, this work presents novel benchmarking results and methods, establishes a new performance baseline for perceptual tasks that provide an alternative window into visual saliency, and demonstrates the capacity for saliency to serve in approximating human behaviour for one visual task given data from another.

2007 IEEE International Conference on Image Processing, 2007

Lecture Notes in Computer Science, 2009

2009 16th IEEE International Conference on Image Processing (ICIP), 2009

ABSTRACT

Cognition & emotion, 2015

In this article, we examine how emotional and perceptual stimulus factors influence visual search... more In this article, we examine how emotional and perceptual stimulus factors influence visual search efficiency. In an initial task, we run a visual search task, using a large number of target/distractor emotion combinations. In two subsequent tasks, we then assess measures of perceptual (rated and computational distances) and emotional (rated valence, arousal and potency) stimulus properties. In a series of regression analyses, we then explore the degree to which target salience (the size of target/distractor dissimilarities) on these emotional and perceptual measures predict the outcome on search efficiency measures (response times and accuracy) from the visual search task. The results show that both emotional and perceptual stimulus salience contribute to visual search efficiency. The results show that among the emotional measures, salience on arousal measures was more influential than valence salience. The importance of the arousal factor may be a contributing factor to contradicto...

Proceedings of the 26th annual ACM symposium on User interface software and technology - UIST '13, 2013

ABSTRACT Mobile devices are endowed with significant sensing capabilities. However, their ability... more ABSTRACT Mobile devices are endowed with significant sensing capabilities. However, their ability to 'see' their surroundings, during active use, is limited. We present Surround-See, a self-contained smartphone equipped with an omni-directional camera that enables peripheral vision around the device to augment daily mobile tasks. Surround-See provides mobile devices with a field-of-view collinear to the device screen. This capability facilitates novel mobile tasks such as, pointing at objects in the environment to interact with content, operating the mobile device at a physical distance and allowing the device to detect user activity, even when the user is not holding it. We describe Surround-See's architecture, and demonstrate applications that exploit peripheral 'seeing' capabilities during active use of a mobile device. Users confirm the value of embedding peripheral vision capabilities on mobile devices and offer insights for novel usage methods.

ABSTRACT In this paper we consider the problem of dynamic range compression from multiple exposur... more ABSTRACT In this paper we consider the problem of dynamic range compression from multiple exposures in the absence of raw images, radiometric response functions, or irradiance information. This is achieved in a rapid and relatively simplistic fashion by merging image content across provided exposures. The premise of the proposal lies in assuming as one important goal of tone-mapping, that of making visible any contrast appearing across a dynamic range that exceeds display capabilities, while preserving the nature of the image structure, lighting, and avoiding introducing discontinuities in illumination, or image artifacts. The strategy assumed for this purpose appeals to the local entropy evident in each exposure, and employs cross-exposure normalization of entropy with a non-linearity characterized by a single parameter providing a trade-off between detail, and smoothness of the result.

Psychological Science, 2008

An object may afford a number of different actions. In this article, we show that an attentional ... more An object may afford a number of different actions. In this article, we show that an attentional mechanism inhibits competing motor programs that could elicit erroneous actions. Participants made a speeded key press to categorize the second of two successively presented door handles that were rotated at varying orientations relative to one another. Their responding hand was compatible or incompatible with the graspable part of the door handles (rightward or leftward facing). Compatible responses were faster than incompatible responses if the two handles shared an identical orientation, but they were slower if the two handles were aligned at slightly dissimilar orientations. Such suppressive surround effects are hallmarks of attentional processing in the visual domain, but they have never been observed behaviorally in the motor domain. This finding delineates a common mechanism involved in two of the most important functions of the brain: processing sensory data and preparing actions based on that information.

Proceedings of the Symposium on Eye Tracking Research and Applications - ETRA '14, 2014

ABSTRACT In this paper, we explore the problem of analyzing gaze patterns towards attributing gre... more ABSTRACT In this paper, we explore the problem of analyzing gaze patterns towards attributing greater meaning to observed fixations. In recent years, there have been a number of efforts that attempt to categorize fixations according to their properties. Given that there are a multitude of factors that may contribute to fixational behavior, including both bottom-up and top-down influences on neural mechanisms for visual representation and saccadic control, efforts to better understand factors that may contribute to any given fixation may play an important role in augmenting raw fixation data. A grand objective of this line of thinking is in explaining the reason for any observed fixation as a combination of various latent factors. In the current work, we do not seek to solve this problem in general, but rather to factor out the role of the holistic structure of a scene as one observable, and quantifiable factor that plays a role in determining fixational behavior. Statistical methods and approximations to achieve this are presented, and supported by experimental results demonstrating the efficacy of the proposed methods.

Neurobiology of Attention, 2005

... Tsotsos casts vision as a massive search problem, but there are other, complementary ... of v... more ... Tsotsos casts vision as a massive search problem, but there are other, complementary ... of visual attention, with emphasis on the circuitry for translation and scale invariance, and the ... 74) distinguish three classes of attentional mechanisms, each with a characteristic per-formance ...

2012 Ninth Conference on Computer and Robot Vision, 2012

ABSTRACT In recent years, many different proposals for visual saliency computation have been put ... more ABSTRACT In recent years, many different proposals for visual saliency computation have been put forth, that generally frame the determination of visual saliency as a measure of local feature contrast. There is however, a paucity of approaches that take into account more global holistic elements of the scene. In this paper, we propose a novel mechanism that augments the visual representation used to compute saliency. Inspired by research into biological vision, this strategy is one based on the role of recurrent computation in a visual processing hierarchy. Unlike existing approaches, the proposed model provides a manner of refining local saliency based computation based on the more global composition of a scene that is independent of semantic labeling or viewpoint. The results presented demonstrate that a fast recurrent mechanism significantly augments the determination of salient regions of interest as compared with a purely feed forward visual saliency architecture. This demonstration is applied to the problem of detecting targets of interest in various surveillance scenarios.

2011 Canadian Conference on Computer and Robot Vision, 2011

ABSTRACT In this paper, we consider the role that visual representation plays in determining the ... more ABSTRACT In this paper, we consider the role that visual representation plays in determining the behavior of a generic model of visual salience. There are a variety of different representations that have been employed to form an early visual representation of image structure. The experiments presented demonstrate that the choice of representation has an appreciable effect on the system behavior. The reasons for these differences are discussed, and generalized to implications for vision systems in general. In instances where a design choice is arbitrary, we look to the properties of visual representation in early visual processing in humans for answers. The results as a whole demonstrate the importance of filter choice and highlight some desirable properties of log-Gabor filters.