OutCast: Outdoor Single-image Relighting with Cast Shadows

We propose a relighting method for outdoor images. Our method mainly focuses on predicting cast shadows in arbitrary novel lighting directions from a single image while also accounting for shading and global effects such the sun light color and clouds. Previous solutions for this problem rely on reconstructing occluder geometry, e.g. using multi-view stereo, which requires many images of the scene. Instead, in this work we make use of a noisy off-the-shelf single-image depth map estimation as a source of geometry. Whilst this can be a good guide for some lighting effects, the resulting depth map quality is insufficient for directly ray-tracing the shadows. Addressing this, we propose a learned image space ray-marching layer that converts the approximate depth map into a deep 3D representation that is fused into occlusion queries using a learned traversal. Our proposed method achieves, for the first time, state-of-the-art relighting results, with only a single image as input. For supplementary material visit our project page at: https://dgriffiths.uk/outcast.Comment: Eurographics 2022 - Accepte

Effect of light intensity, light duration and photoperiods in the performance of an outdoor photobioreactor for urban wastewater treatment

[EN] A series of eight experiments were carried out to analyse the effects of light intensity, light duration and photoperiods on a microalgae culture for treating AnMBR effluent at an outdoor photobioreactor (PBR) plant. Improved performance was achieved in terms of nutrient recovery rates, biomass productivity and effluent nutrient concentrations at a higher net photon flux. However, the higher irradiance was also responsible for lower biomass productivity:light irradiance ratios. None of the experiments with different lighting regimes and the same net photon flux showed any significant differences. The data obtained suggest that microalgae performance in this system did not depend on the time of day when light was applied or the length of the photoperiods, but on the net photon flux. No photoinhibiton was observed in any of the experiments, probably because of the significant shadow effect on the microalgae in the PBRs.This research work was supported by the Spanish Ministry of Economy and Competitiveness (MINECO, Projects CTM2014-54980-C2-1-R, CTM2014-54980-C2-2-R, CTM2011-28595-C02-01, and CTM2011-28595-C02-02) jointly with the European Regional Development Fund (ERDF), both of which are gratefully acknowledged. It was also supported by the Spanish Ministry of Education, Culture and Sport via a pre-doctoral FPU fellowship to author J. González-Camejo (FPU14/05082).Gonzalez-Camejo, J.; Viruela Navarro, A.; Ruano García, MV.; Barat, R.; Seco Torrecillas, A.; Ferrer, J. (2019). Effect of light intensity, light duration and photoperiods in the performance of an outdoor photobioreactor for urban wastewater treatment. Algal Research. 40:1-11. https://doi.org/10.1016/j.algal.2019.101511S1114

DeepDR: Deep Structure-Aware RGB-D Inpainting for Diminished Reality

Diminished reality (DR) refers to the removal of real objects from the environment by virtually replacing them with their background. Modern DR frameworks use inpainting to hallucinate unobserved regions. While recent deep learning-based inpainting is promising, the DR use case is complicated by the need to generate coherent structure and 3D geometry (i.e., depth), in particular for advanced applications, such as 3D scene editing. In this paper, we propose DeepDR, a first RGB-D inpainting framework fulfilling all requirements of DR: Plausible image and geometry inpainting with coherent structure, running at real-time frame rates, with minimal temporal artifacts. Our structure-aware generative network allows us to explicitly condition color and depth outputs on the scene semantics, overcoming the difficulty of reconstructing sharp and consistent boundaries in regions with complex backgrounds. Experimental results show that the proposed framework can outperform related work qualitatively and quantitatively.Comment: 11 pages, 8 figures + 13 pages, 10 figures supplementary. Accepted at 3DV 202

Occlusion handling in multiple people tracking

Object tracking with occlusion handling is a challenging problem in automated video surveillance. Occlusion handling and tracking have always been considered as separate modules. We have proposed an automated video surveillance system, which automatically detects occlusions and perform occlusion handling, while the tracker continues to track resulting separated objects. A new approach based on sub-blobbing is presented for tracking objects accurately and steadily, when the target encounters occlusion in video sequences. We have used a feature-based framework for tracking, which involves feature extraction and feature matching

Adaptive foreground segmentation using fuzzy approach

Intelligent visual surveillance which attempts to detect, recognize and track certain objects from image sequences is becoming an active research topic in computer vision community. Background modeling and foreground segmentation are the first two and the most important steps in any intelligent visual surveillance systems. The accuracy of these two steps highly effects performance of the following steps. In this thesis, we propose a simple and novel method which employs histogram based median method for background modeling and a fuzzy k-Means clustering approach for foreground segmentation. Experiments on a set of videos and benchmark image sequences show the effectiveness of the proposed method. Compared with other two contemporary methods - k -Means clustering and Mixture of Gaussians (MoG) - the proposed method is not only time efficient but also provides better segmentation results

겨울도시를 위한 기후민감형 도시설계 — 캐나다 에드먼턴 오픈스페이스 사례를 중심으로 —

학위논문 (석사) -- 서울대학교 대학원 : 공과대학 협동과정 도시설계학전공, 2020. 8. Yumi Lee.본 연구는 캐나다 에드먼턴의 미래 오픈스페이스에 대한 계획과 가상의 설계를 제안하여 겨울을 포함한 모든 계절에 활용할 수 있도록 하는 것을 목적으로 한다. 본 연구의 결과는 기후민감형 도시설계에 대한 고려사항이 겨울도시에서 연중 내내 기능적인 공간을 만드는데 필수적인 부분이라고 주장한다. 현재까지 설계된 대다수의 오픈스페이스는 일년내내, 사계절 동안 기능할 수 없다. 겨울은 항상 실내에 머물기 위한 계절이었고, 여름은 항상 야외활동을 즐기는 계절이었다. 이러한 사고방식은 전 세계의 계획 관행에 뿌리내렸고 겨울 민감형 계획으로의 변화를 조금씩 시작하고 있다. 1980년 이후 컨퍼런스 및 세계 행사들은 겨울 생활 문제를 인정해왔지만, 현재까지 계획관행은 여전히 여름의 사고방식에 바탕을 둔 디자인이다. 겨울과 계절에 따른 온도변화가 우리의 일상에 영향을 미치며, 특히 겨울철에 디자인방식은 공간이 어떻게 사용되는지에 많은 영향을 줄 수 있음을 이해하는 것이 중요하다 낮은 기온, 미끄러움, 어두움과 같은 불편함은 겨울철 야외 공간을 계획하는 데 고려되지 않는 요인들이다. 본 연구의 목적은 캐나다 북부 도시 에드먼턴에서 기후민감형 설계요소들을 활용하여 미래의 공공 도시 공간을 가상으로 설계하는 것이다. 본 연구는 캐나다 에드먼턴에 있는 미래 웨어하우스 캠퍼스 공원(Warehouse Campus Park)의 가상설계를 위해 기존문헌, 설문조사 및 심층인터뷰의 결과를 적용했다. 설문조사 결과는 공공 공간을 사용하는 주된 이유가 축제나 이벤트와 같은 프로그램을 위한 것임을 보여준다. 미래 공간의 설계는 축제일이 아닌 날에도 사용자를 끌어들일 수 있도록 연중 기능성의 요소를 통합하는 것이 필수적이다. 기후민감형 설계의 주요 장벽은 운영 및 유지 관리 문제뿐만 아니라 겨울은 견뎌야하며, 환영받지 못하는 계절이라는 사고방식을 포함한다. 에드먼턴 있는 도시계획가와의 인터뷰에서 에드먼턴 겨울 디자인 가이드라인(Winter Design Guidelines)의 가장 큰 장애물은 해당 문서가 비규제적이어서 시행하기 어렵다는 것이다. 그러나 최근 몇 년 동안 연중 사용 가능한 공간에 대한 민간 개발자 및 커뮤니티의 관심이 증가하고 있다. 심층 인터뷰의 대상자에게 제시된 개념적 설계는 에드먼턴 시가 지역사회 녹색공간 조성을 검토하고 있음을 단적으로 보여준다. 에드먼턴 다운타운이 가장 부족한 것은 열린녹지공간과 어린이 놀이 공간인 만큼 미래의 디자인에서 이러한 요구를 충족시키는 것이 중요하다. 에드먼턴의 도시 형태와 계획 관행을 바꾸는 것은 느리게 진행되어 왔으며, 겨울도시를 위한 기후민감형 도시설계는 거의 10년 전에 도입되었지만, 이러한 설계는 여전히 도시의 개발자들에게 상당히 새로운 개념이다. 겨울도시를 위한 기후민감형 도시설계는 공공 오픈스페이스 공간뿐만 아니라 일반적인 공공 영역에도 적용 되어야한다. 도시설계와 계획의 사전 단계에서 구체적인 고려를 하지 않는 한 추운 날씨와 겨울의 불편함은 계속해서 겨울을 즐기는데 장애가 될 것이다. 본 연구의 설계는 완벽한 디자인을 제시하는 것이 아니라, 북부 국가에서 매우 필요한 기후민감형 도시설계의 주제에 관여하는 설계이다. 본 연구의 결과는 도시 디자이너들이 추운 겨울 동안 어떻게 다양한 문화와 사람들의 요구를 충족시킬 수 있는지를 알려주는 데 도움이 될 것이다.This project proposes recommendations and a hypothetical design of a future public space in Edmonton, Canada that will be functional in all seasons, including the winter. The results of this research argue that climate sensitive design considerations in the early stages of planning and design are a vital part of creating year-round functional space in winter cities. Winter was always the season to stay indoors, and the summer was to enjoy the outdoors. This mindset caused the designs of the public realms to lack for four season, year-round usage. Conferences and world events since the 1980s acknowledged the difficulties of winter living but planning practices to date are still design based on the summer mindset. Although there has been neglect for addressing winter discomforts in Nordic cities, winter sensitive considerations are slowly beginning to be a topic of discussion. It is essential to understand that winter and the change of seasonal temperatures affect our annual daily lives, and design considerations can severely impact how spaces are used, especially in the winter. Discomforts such as coldness, slipperiness, and darkness are some of the neglected considerations for planning outdoor spaces in the winter season. The purpose of this study was to hypothetically design a future public urban space using climate-sensitive considerations in the northern city of Edmonton, Canada. This study applied recommendations and feedback from existing literature, questionnaire results, and in-depth interviews into the design proposal of the future Warehouse Campus Park in Edmonton, Canada. Results from the questionnaire illustrated that the main reasons for using public spaces were for programming, such as festivals and events. Future spaces must incorporate elements of year-round functionality that could attract users even on non-festival days. The main barriers that climates sensitive design considerations included operational and maintenance issues, and the mindset that winter continues to be a season that needs to be endured and not celebrated. Interviews with local planners determined that the most significant hurdle to the incorporating climate sensitive design considerations in Edmonton, was that tie Winter Deign Guidelines are non-regulatory, making it difficult to enforce. However, in recent years, there has been an increase in interest from private developers and communities for year-round usable spaces. The conceptual designs presented in the in-depth interview outlined that the City of Edmonton is looking at creating a community green space. Downtown Edmonton lacks in open green spaces and childrens play areas; therefore, it is crucial to account for those needs in future designs. It is essential to understand that changing the urban form and planning practices in Edmonton has been a slow process. Although the introduction of winter city design was nearly ten years ago, designing for climate sensitive considerations is still a relatively new concept for developers in the city. Climate sensitive design considerations not only apply to public open spaces but to the public realm in general. This project informs how urban designers can cater to diverse cultures and needs of the population during the colder winter months. Cold temperatures and winter discomforts will continue to be a barrier to the winter enjoyment unless preliminary stages of planning and design include detailed climate sensitive considerations. The purpose of the design proposal was to address winter discomforts in Edmonton and engage in further discussion in the topic of climate sensitive considerations for northern cities.1.0 Introduction 1 1.1. Background 1 1.2. Winter Cities Movement 3 1.3. Research Questions 4 1.4. Research Purpose 4 1.5. Project Scope 5 1.6. Methodology 6 2.0 About Edmonton 7 2.1. General Information 7 2.2. Edmonton Weather 9 2.3. Winter City Edmonton 9 2.4. Downtown Edmonton 12 2.5. Edmontons Green Network Strategy 15 2.6. Warehouse Campus Neighbourhood Central Park 15 2.6.1. Downtown Public Places Plan 17 3.0 Literature Review 18 3.1. Introduction 18 3.2. Outdoor Comfort 18 3.2.1. Thermal Comfort 18 3.2.2. Wind Comfort 21 3.3. Winter City Design 24 3.3.1. Barriers to Winter City Design 24 3.3.2. Recommendations for Winter City Design 26 3.4. Designing for the User Experience 32 3.4.1. Space for All Users 32 3.4.2. Challenges of Downtown Open Spaces 33 3.4.3. Year-round Public Places 34 3.4.4. Human Scale Elements 35 3.4.5. Crime Prevention Through Environmental Design (CPTED) 36 4.0 Site Planning 38 4.1. Introduction 38 4.2. Questionnaire 38 4.2.1. Purpose 38 4.2.2. Methodology 39 4.2.3. Design 39 4.2.4. Limitations 40 4.3. Questionnaire Results 41 4.3.1. Reasons and barriers of using public spaces in the winter 45 4.3.2. Perceptions of designing for climate sensitive spaces 48 4.3.3. Vision for the Future Warehouse Campus Park 52 4.3.4. Conclusions 59 4.4. Warehouse Campus 60 4.4.1. Introduction 60 4.4.2. Site Visit 61 4.5. Site Analysis 64 4.5.1. Surrounding Conditions 65 4.5.2. Environmental Conditions 74 5.0 Design Proposal 83 5.1. Guiding Principles 83 5.2. Proposed Programming 84 5.2.1. Conceptual Designs 85 5.3. In-Depth Interview 87 5.3.1. Winter Design Guidelines 88 5.3.2. Potential for Winter Activities 91 5.3.3. Climate Sensitive Considerations 95 5.3.4. Conceptual Design Evaluations 100 5.4. Proposed Design 107 5.5. Detailed Programming 110 6.0 Conclusion 120 6.1. Designing for Winter Cities 120 6.2. Project Limitations 121 6.3. Future Considerations 122 Bibliography 124 Appendix 129 Abstract in Korean 136Maste

Illumination Variance In Video Processing

Doctor of Philosophy and was awarded by Brunel University LondonInthisthesiswefocusontheimpactofilluminationchangesinvideoand we discuss how we can minimize the impact of illumination variance in video processing systems. Identifyingandremovingshadowsautomaticallyisaverywellestablished and an important topic in image and video processing. Having shadowless image data would benefit many other systems such as video surveillance, tracking and object recognition algorithms. Anovelapproachtoautomaticallydetectandremoveshadowsispresented in this paper. This new method is based on the observation that, owing to the relative movement of the sun, the length and position of a shadow changes linearly over a relatively long period of time in outdoor environments,wecanconvenientlydistinguishashadowfromotherdark regions in an input video. Then we can identify the Reference Shadow as the one with the highest confidence of the mentioned linear changes. Once one shadow is detected, the rest of the shadow can also be identifiedandremoved. Wehaveprovidedmanyexperimentsandourmethod is fully capable of detecting and removing the shadows of stationary and moving objects. Additionally we have explained how reference shadows can be used to detect textures that reflect the light and shiny materials such as metal, glass and water. ..

Background Subtraction in Video Surveillance

The aim of thesis is the real-time detection of moving and unconstrained surveillance environments monitored with static cameras. This is achieved based on the results provided by background subtraction. For this task, Gaussian Mixture Models (GMMs) and Kernel density estimation (KDE) are used. A thorough review of state-of-the-art formulations for the use of GMMs and KDE in the task of background subtraction reveals some further development opportunities, which are tackled in a novel GMM-based approach incorporating a variance controlling scheme. The proposed approach method is for parametric and non-parametric and gives us the better method for background subtraction, with more accuracy and easier parametrization of the models, for different environments. It also converges to more accurate models of the scenes. The detection of moving objects is achieved by using the results of background subtraction. For the detection of new static objects, two background models, learning at different rates, are used. This allows for a multi-class pixel classification, which follows the temporality of the changes detected by means of background subtraction. In a first approach, the subtraction of background models is done for parametric model and their results are shown. The second approach is for non-parametric models, where background subtraction is done using KDE non-parametric model. Furthermore, we have done some video engineering, where the background subtraction algorithm was employed so that, the background from one video and the foreground from another video are merged to form a new video. By doing this way, we can also do more complex video engineering with multiple videos. Finally, the results provided by region analysis can be used to improve the quality of the background models, therefore, considerably improving the detection results

Enhancing the Visible with the Invisible: Exploiting Near-Infrared to Advance Computational Photography and Computer Vision

Silicon-based digital camera sensors exhibit significant sensitivity beyond the visible spectrum (400-700nm). They are able to capture wavelengths up to 1100 nm, i.e., they are sensitive to near-infrared (NIR) radiation. This additional information is conventionally treated as noise and is absorbed by a NIR-blocking filter affixed to the sensor. We show that retaining instead of removing NIR information can significantly improve certain computational photography and computer vision tasks. Indeed, intrinsic properties of the NIR wavelength band guarantee that images can be sharper, less affected by man-made colorants, and more resilient to changing light conditions. The benefits of using NIR images in conjunction with standard color images in applications such as haze removal, skin smoothing, single and multiple illuminant detection, shadow detection, and material classification is discussed

The Profits of Insanity: The Urbanization and Economic Development of Asylum Poor Farms in Wisconsin, 1890-1920

A primary source research project and term paper on the intersection of poverty and insanity and the exploitation of inane labor at Wisconsin county asylums 1890-1920