A Self-Organizing Neural System for Learning to Recognize Textured Scenes

A self-organizing ARTEX model is developed to categorize and classify textured image regions. ARTEX specializes the FACADE model of how the visual cortex sees, and the ART model of how temporal and prefrontal cortices interact with the hippocampal system to learn visual recognition categories and their names. FACADE processing generates a vector of boundary and surface properties, notably texture and brightness properties, by utilizing multi-scale filtering, competition, and diffusive filling-in. Its context-sensitive local measures of textured scenes can be used to recognize scenic properties that gradually change across space, as well a.s abrupt texture boundaries. ART incrementally learns recognition categories that classify FACADE output vectors, class names of these categories, and their probabilities. Top-down expectations within ART encode learned prototypes that pay attention to expected visual features. When novel visual information creates a poor match with the best existing category prototype, a memory search selects a new category with which classify the novel data. ARTEX is compared with psychophysical data, and is benchmarked on classification of natural textures and synthetic aperture radar images. It outperforms state-of-the-art systems that use rule-based, backpropagation, and K-nearest neighbor classifiers.Defense Advanced Research Projects Agency; Office of Naval Research (N00014-95-1-0409, N00014-95-1-0657

Saliency-based image enhancement

Ph.DDOCTOR OF PHILOSOPH

Non-Visual Representation of Complex Documents for Use in Digital Talking Books

Essential written information such as text books, bills, and catalogues needs to be accessible by everyone. However, access is not always available to vision-impaired people. As they require electronic documents to be available in specific formats. In order to address the accessibility issues of electronic documents, this research aims to design an affordable, portable, standalone and simple to use complete reading system that will convert and describe complex components in electronic documents to print disabled users

Affective Computing

This book provides an overview of state of the art research in Affective Computing. It presents new ideas, original results and practical experiences in this increasingly important research field. The book consists of 23 chapters categorized into four sections. Since one of the most important means of human communication is facial expression, the first section of this book (Chapters 1 to 7) presents a research on synthesis and recognition of facial expressions. Given that we not only use the face but also body movements to express ourselves, in the second section (Chapters 8 to 11) we present a research on perception and generation of emotional expressions by using full-body motions. The third section of the book (Chapters 12 to 16) presents computational models on emotion, as well as findings from neuroscience research. In the last section of the book (Chapters 17 to 22) we present applications related to affective computing

Non-visual representation of complex documents for use in digital talking books

According to a World Intellectual Property Organization (WIPO) estimation, only 5% of the world's one million print titles that are published every year are accessible to the approximately 340 million blind, visually impaired or print disabled people. Equal access to information is a basic right of all people. Essen- tial information such as flyers, brochures, event calendars, programs, catalogues and booking information needs to be accessible by everyone. Information helps people to make decisions, be involved in society and live independent lives. Ar- ticle 21, Section 4.2. of the United Nation's Convention on the rights of people with disabilities advocates the right of blind and partially sighted people to take control of their own lives. However, this entitlement is not always available to them without access to information. Today, electronic documents have become pervasive. For vision-impaired people electronic documents need to be available in specific formats to be accessible. If these formats are not made available, vision-impaired people are greatly disadvantaged when compared to the general population. Therefore, addressing electronic document accessibility for them is an extremely important concern. In order to address the accessibility issues of electronic documents, this research aims to design an affordable, portable, stand-alone and simple to use "Complete Reading System" to provide accessible electronic documents to vision impaired

Implementing non-photorealistic rendreing enhancements with real-time performance

We describe quality and performance enhancements, which work in real-time, to all well-known Non-photorealistic (NPR) rendering styles for use in an interactive context. These include Comic rendering, Sketch rendering, Hatching and Painterly rendering, but we also attempt and justify a widening of the established definition of what is considered NPR. In the individual Chapters, we identify typical stylistic elements of the different NPR styles. We list problems that need to be solved in order to implement the various renderers. Standard solutions available in the literature are introduced and in all cases extended and optimised. In particular, we extend the lighting model of the comic renderer to include a specular component and introduce multiple inter-related but independent geometric approximations which greatly improve rendering performance. We implement two completely different solutions to random perturbation sketching, solve temporal coherence issues for coal sketching and find an unexpected use for 3D textures to implement hatch-shading. Textured brushes of painterly rendering are extended by properties such as stroke-direction and texture, motion, paint capacity, opacity and emission, making them more flexible and versatile. Brushes are also provided with a minimal amount of intelligence, so that they can help in maximising screen coverage of brushes. We furthermore devise a completely new NPR style, which we call super-realistic and show how sample images can be tweened in real-time to produce an image-based six degree-of-freedom renderer performing at roughly 450 frames per second. Performance values for our other renderers all lie between 10 and over 400 frames per second on homePC hardware, justifying our real-time claim. A large number of sample screen-shots, illustrations and animations demonstrate the visual fidelity of our rendered images. In essence, we successfully achieve our attempted goals of increasing the creative, expressive and communicative potential of individual NPR styles, increasing performance of most of them, adding original and interesting visual qualities, and exploring new techniques or existing ones in novel ways.KMBT_363Adobe Acrobat 9.54 Paper Capture Plug-i

Targeting Cerebral Oedema and Elevated Intracranial Pressure in a Preclinical Model of Ischaemic Stroke

Stroke is a devastating condition, affecting over 17 million people worldwide annually. Interruption of cerebral arterial blood flow in ischaemic stroke initiates a cascade of deleterious events, leading to irreversible cell damage and secondary injury. Specifically, the development of cerebral oedema, whereby disruption to the blood–brain barrier (BBB) precipitates abnormal fluid accumulation within the brain parenchyma, leads to a consequent rise in intracranial pressure (ICP). Persistently elevated ICP results in loss of cerebral autoregulation and brain herniation, making it a leading cause of death and disability poststroke. Despite this, current treatments fail to prevent the pathophysiological development of oedema, rather targeting the symptoms once established. As such, understanding the mechanisms underlying cerebral oedema and elevated ICP is essential in order to develop more targeted and effective treatments to prevent oedema genesis and improve patient outcomes. Neurogenic inflammation, mediated by substance P (SP), has been linked to profound BBB disruption, oedema development and poor functional outcome post-stroke. SP binds to the neurokinin 1 tachykinin receptor (NK1-R), with administration of an NK1-R antagonist shown to ameliorate BBB dysfunction and cerebral oedema following stroke in rodent models. However, more clinically-relevant animal models are required to validate efficacy of novel stroke therapeutics to improve clinical translation. Thus, this thesis sought to determine the efficacy of NK1-R antagonist treatment in reducing cerebral oedema and ICP in a clinically-relevant ovine stroke model. Merino sheep (Ovis aries; n=125) were used across the five thesis studies. For Aim 1 (n=34F), a non-survival permanent middle cerebral artery occlusion (MCAo) model was used to determine the efficacy of various NK1-R receptor antagonist regimens or decompressive craniectomy in reducing ICP post-stroke. Once an optimum dosage was determined, Aims 2 and 3 (n=23F;24M) involved development of a transient MCAo survival model and characterisation of the temporal profile of oedema and ICP. Finally, Aim 4 and 5 (n=9F;9M), sought to determine the ideal time-course of treatment, and investigate the efficacy of the NK1-R antagonist following transient stroke via assessment of neurological and functional outcomes. ICP was assessed via invasive monitoring, with arterial blood pressure, temperature and blood gases also measured. Magnetic resonance imaging (MRI) and immunohistochemistry (IHC) was also performed. Motion capture and a modified neuroscore was used to assess changes in motor function and demeanour. This thesis identified that two doses of the NK1-R antagonist were efficacious in reducing ICP following permanent MCAo. A transient stroke model was successfully developed and characterised, with ICP peaking at 5-6 days post-stroke. NK1-R antagonist treatment, both acutely (1-3 days), and in a delayed fashion (5-day), significantly reduced ICP post-stroke. Finally, a motion capture tool was successfully established and validated as a quantitative method to assess motor function following transient ovine stroke, with animal gait significantly impaired post-stroke. The work presented in this thesis encompasses a comprehensive evaluation of the efficacy of NK1-R antagonist treatment in a clinically-relevant ovine model, providing strong preclinical evidence for further investigation. Accordingly, Phase II trials are currently underway in Australia, the United Kingdom and the United States of America.Thesis (Ph.D.) -- University of Adelaide, Adelaide Medical School, 202