Real-Time RGB-D Camera Pose Estimation in Novel Scenes using a Relocalisation Cascade

Camera pose estimation is an important problem in computer vision. Common techniques either match the current image against keyframes with known poses, directly regress the pose, or establish correspondences between keypoints in the image and points in the scene to estimate the pose. In recent years, regression forests have become a popular alternative to establish such correspondences. They achieve accurate results, but have traditionally needed to be trained offline on the target scene, preventing relocalisation in new environments. Recently, we showed how to circumvent this limitation by adapting a pre-trained forest to a new scene on the fly. The adapted forests achieved relocalisation performance that was on par with that of offline forests, and our approach was able to estimate the camera pose in close to real time. In this paper, we present an extension of this work that achieves significantly better relocalisation performance whilst running fully in real time. To achieve this, we make several changes to the original approach: (i) instead of accepting the camera pose hypothesis without question, we make it possible to score the final few hypotheses using a geometric approach and select the most promising; (ii) we chain several instantiations of our relocaliser together in a cascade, allowing us to try faster but less accurate relocalisation first, only falling back to slower, more accurate relocalisation as necessary; and (iii) we tune the parameters of our cascade to achieve effective overall performance. These changes allow us to significantly improve upon the performance our original state-of-the-art method was able to achieve on the well-known 7-Scenes and Stanford 4 Scenes benchmarks. As additional contributions, we present a way of visualising the internal behaviour of our forests and show how to entirely circumvent the need to pre-train a forest on a generic scene.Comment: Tommaso Cavallari, Stuart Golodetz, Nicholas Lord and Julien Valentin assert joint first authorshi

Knowledge, Food and Place: a way of producing a way of knowing

The article examines the dynamics of knowledge in the valorisation of local food, drawing on the results from the CORASON project (A cognitive approach to rural sustainable development: the dynamics of expert and lay knowledge), funded by the EU under its Framework Programme 6. It is based on the analysis of several in-depth case studies on food relocalisation carried out in 10 European countries

Resilient Maroochydore 2029 : Urban Design Futures

Resilient Maroochydore 2029 This exhibition showcases the work of 4th year undergraduate Landscape Architecture students in response to issues of sustainability in Maroochydore on the Queensland Sunshine coast. The projects comprising this exhibition all investigate possible design futures for the Maroochydore Centre, in the light of a series of new disturbance scenarios. Specific disturbances upon the landscape have been imagined, and design resolutions developed based on resilience to these disturbances. The proposals investigate how the Maroochydore Centre might respond to these scenarios, and how future components of the Centre might be designed for greater ‘resilience’. The Exhibition Five groups of students (32 in total) produced five strategic planning and design options toward this future: Team Transect: “What happens to a region following a sustained period of economic prosperity, with affordable property and negligible unemployment? This proposal investigates the effects on a community of massive population explosion, land shortages and inadequate planning regulations following an extended boom period.” The Foodfighters: “This proposal considers the scenario of massive food shortages and of escalating prices, and the possibility of government intervention to stabilise food supply. Strategies based upon simplified, collaborative approaches to food production are investigated.” The TTMKG: “This proposal explores the scenario of Peak Oil and the subsequent effects on society of homelessness, large scale unemployment, food shortages and global financial and political instability. Individual opportunities are restricted by the limitations of bicycle transportation.” Team Peak: “Peak Oil has restricted private vehicle transport to only the most wealthy, while public transport systems are under immense pressure. Rising unemployment drives localised trade initiatives, and the global import/export market has collapsed. This proposal considers the transition of a community from its position in a global economy to that of a relocalised economy, where basic needs are secured as close to home as possible.” After the City: “A rapid population decline as a result of the region’s failing economy has resulted in a fragmented urban fabric. This proposal investigates the possibility of new suburbanisation, reinterpretation and reinvention of space through phased processes.

InfiniTAM v3: A Framework for Large-Scale 3D Reconstruction with Loop Closure

Volumetric models have become a popular representation for 3D scenes in recent years. One breakthrough leading to their popularity was KinectFusion, which focuses on 3D reconstruction using RGB-D sensors. However, monocular SLAM has since also been tackled with very similar approaches. Representing the reconstruction volumetrically as a TSDF leads to most of the simplicity and efficiency that can be achieved with GPU implementations of these systems. However, this representation is memory-intensive and limits applicability to small-scale reconstructions. Several avenues have been explored to overcome this. With the aim of summarizing them and providing for a fast, flexible 3D reconstruction pipeline, we propose a new, unifying framework called InfiniTAM. The idea is that steps like camera tracking, scene representation and integration of new data can easily be replaced and adapted to the user's needs. This report describes the technical implementation details of InfiniTAM v3, the third version of our InfiniTAM system. We have added various new features, as well as making numerous enhancements to the low-level code that significantly improve our camera tracking performance. The new features that we expect to be of most interest are (i) a robust camera tracking module; (ii) an implementation of Glocker et al.'s keyframe-based random ferns camera relocaliser; (iii) a novel approach to globally-consistent TSDF-based reconstruction, based on dividing the scene into rigid submaps and optimising the relative poses between them; and (iv) an implementation of Keller et al.'s surfel-based reconstruction approach.Comment: This article largely supersedes arxiv:1410.0925 (it describes version 3 of the InfiniTAM framework

Introduction: food relocalisation and knowledge dynamics for sustainability in rural areas

The chapter presents the literature on local food and local knowledge and introduces the case studies analysed in the volum

Explaining Regional and Local Differences in Organic Farming in England and Wales: A Comparison of South West Wales and South East England

Explaining regional and local differences in organic farming in England and Wales: a comparison of South West Wales and South East England, Regional Studies, Few studies explain the concentration of organic farming in specific regions of England and Wales. This paper compares the development of organic farming in South West Wales and South East England. While the focus in the former is on the use of mainly national marketing channels and the movement of organic produce more than 60 min from the farm, in the latter greater use is made of local and direct marketing channels to distribute organic food within 30 min of the farm. The overriding importance of demand appears to provide a key explanation for regional differentiation in organic farming. 解释英格兰与威尔斯有机农业的区域及地方差异：西南威尔斯与东南英格兰的比较研究，区域研究。显少有研究解释有机农业在英格兰及威尔斯特定区域中的集中现象。本文比较有机农业在西南威尔斯与东南英格兰的发展。西南威尔斯的发展重点，主要在于利用全国行销通路，以及距离农场超过六十分钟的有机产品运送路程，东南英格兰则较着重运用在地且直接的行销通路，在距离农场三十分钟以内的运送路程中分派有机食品。需求的压倒性重要性，似乎提供了有机农业中的区域差异的关键解释。 Expliquer les disparités régionales dans l'agriculture biologique en Angleterre et au pays de Galles: une comparaison du sud-ouest du pays de Galles et du sud-est de l'Angleterre, Regional Studies. Rares sont les études qui expliquent la concentration de l'agriculture biologique dans des zones spécifiques de l'Angleterre et du pays de Galles. Cet article cherche à comparer le développement de l'agriculture biologique du sud-ouest du pays de Galles à celle du sud-est de l'Angleterre. Tandis que celle-là met l'accent sur l'emploi des circuits commerciaux principalement nationaux et sur la distribution de la production agricole biologique à plus de 60 minutes de la ferme, celle-ci exploite davantage les circuits commerciaux locaux et directs pour distribuer les denrées alimentaires organiques dans un rayon de 30 minutes de la ferme. Il semble que l'importance primordiale de la demande constitue un facteur déterminant de la différenciation régionale de l'agriculture biologique. Erklärung der regionalen und lokalen Unterschiede bei der ökologischen Landwirtschaft in England und Wales: ein Vergleich zwischen Südwestwales und Südostengland, Regional Studies. Die Konzentration der ökologischen Landwirtschaft in bestimmten Regionen von England und Wales wird nur in wenigen Studien erklärt. In diesem Beitrag vergleichen wir die Entwicklung der ökologischen Landwirtschaft in Südwestwales mit der von Südostengland. Während in Südwestwales der Schwerpunkt auf den größtenteils landesweiten Absatzkanälen und dem Transport von ökologischen Lebensmitteln an mehr als 60 Minuten vom landwirtschaftlichen Betrieb entfernte Orte liegt, werden in Südostengland öfter lokale und direkte Absatzkanäle genutzt und die ökologischen Lebensmittel an bis zu 30 Minuten vom landwirtschaftlichen Betrieb entfernte Orte transportiert. Die wichtigste Erklärung für die regionalen Unterschiede bei der ökologischen Landwirtschaft scheinen in der vorrangigen Bedeutung der Nachfrage zu liegen. Explicación de las diferencias regionales y locales en la agricultura biológica de Inglaterra y Gales: comparación entre el suroeste de Gales y el sureste de Inglaterra, Regional Studies. En pocos estudios se explica la concentración de la agricultura biológica en regiones específicas de Inglaterra y Gales. En este artículo comparamos el desarrollo de la agricultura biológica en el suroeste de Gales y el sureste de Inglaterra. Mientras que en el suroeste de Gales se hace hincapié en el uso de canales mercantiles principalmente nacionales y el movimiento de productos biológicos a una distancia de más de 60 minutos de la explotación agrícola, en el sureste de Inglaterra se utilizan más los canales mercantiles locales y directos para distribuir alimentos biológicos a no más de 30 minutos de la explotación agrícola. Parece ser que la demanda es el motivo más importante para explicar las diferencias regionales en la agricultura biológica

Contending European agendas for agricultural innovation

Amid expectations for a European ‘transition to sustainable agriculture’, there are competing transitional processes. Given the widely acknowledged harm from agro-industrial systems, ‘unsustainable agriculture’ has divergent diagnoses and innovative solutions. This rivalry can be analysed as contending innovation agendas; the analysis here combines theoretical paradigms of agricultural innovation. In an EU policy context of a Knowledge-Based Bio-Economy (KBBE), there are divergent accounts of its key terms: biological resources, economy, relevant knowledge and knowledge-producers. Likewise, divergent accounts are found of innovation, intensification, resource efficiency, resilience, bio-energy, horizontal integration, etc. These divergent agendas are promoted by distinct stakeholder networks. The dominant agenda favours laboratory-based techno-scientific innovation as a source of ‘efficient’ inputs, which can use renewable resources more efficiently for competitive advantage in global value chains. By contrast, other agendas promote farmers’ knowledge of natural resources, especially via agro-ecological methods which can reduce energy inputs, increase productivity and add value through quality. With those contending agendas, rival stakeholder networks seek to influence R&D priorities. From the standpoint of multifunctional agriculture, such contending agendas can play complementary roles in different rural spaces. Some agro-food practices may combine aspects of different paradigms. As a concept, Agricultural Knowledge Systems may provide a common space for interchanges between divergent agendas and their research priorities. However, these innovation agendas promote conflicting visions of the future

Transition in place: dynamics, possibilities, and constraints

The Transition Movement is a translocal phenomenon circulated through transnational grassroots networks. This study explores the geographies of the Transition Movement with a theoretical framework that perceives it as both a social movement and a grassroots innovation. Participant-observation of Transition Salt Lake (TSL), located in the suburban metropolis of Salt Lake City, Utah, was conducted, as the United States remains a largely understudied country in regards to this particular movement. In this pursuit, we asked: (i) how and what this transition initiative draws from geographically extensive and intensive relations, (ii) how it combines place-specific elements and generalized models (embeddedness), and (iii) how this impacts the success of the transition initiative and how these impacts (positive or negative) are generated. Place, space, and scale played a large role in defining the nature, dynamics, possibilities, and constraints of this transition initiative. Specifically, geographically intensive and extensive relations were critical for the mobilization of complementary resources. The Transition model was found to be flexible, allowing for the initiative to adopt those elements that worked in place and to focus on locally relevant topics. TSL faced many challenges identified by previous researchers regarding finances, participation, diversity, and intragroup competition. While networking with other similar groups, TSL demonstrated that fertile environments of activism are incubatory pools for grassroots innovations and social movements, and a trade-off was found with competition for resources between local groups

UcoSLAM: Simultaneous Localization and Mapping by Fusion of KeyPoints and Squared Planar Markers

This paper proposes a novel approach for Simultaneous Localization and Mapping by fusing natural and artificial landmarks. Most of the SLAM approaches use natural landmarks (such as keypoints). However, they are unstable over time, repetitive in many cases or insufficient for a robust tracking (e.g. in indoor buildings). On the other hand, other approaches have employed artificial landmarks (such as squared fiducial markers) placed in the environment to help tracking and relocalization. We propose a method that integrates both approaches in order to achieve long-term robust tracking in many scenarios. Our method has been compared to the start-of-the-art methods ORB-SLAM2 and LDSO in the public dataset Kitti, Euroc-MAV, TUM and SPM, obtaining better precision, robustness and speed. Our tests also show that the combination of markers and keypoints achieves better accuracy than each one of them independently.Comment: Paper submitted to Pattern Recognitio