Generative Street Addresses from Satellite Imagery

We describe our automatic generative algorithm to create street addresses from satellite images by learning and labeling roads, regions, and address cells. Currently, 75% of the world’s roads lack adequate street addressing systems. Recent geocoding initiatives tend to convert pure latitude and longitude information into a memorable form for unknown areas. However, settlements are identified by streets, and such addressing schemes are not coherent with the road topology. Instead, we propose a generative address design that maps the globe in accordance with streets. Our algorithm starts with extracting roads from satellite imagery by utilizing deep learning. Then, it uniquely labels the regions, roads, and structures using some graph- and proximity-based algorithms. We also extend our addressing scheme to (i) cover inaccessible areas following similar design principles; (ii) be inclusive and flexible for changes on the ground; and (iii) lead as a pioneer for a unified street-based global geodatabase. We present our results on an example of a developed city and multiple undeveloped cities. We also compare productivity on the basis of current ad hoc and new complete addresses. We conclude by contrasting our generative addresses to current industrial and open solutions. Keywords: road extraction; remote sensing; satellite imagery; machine learning; supervised learning; generative schemes; automatic geocodin

View Rendering for 3DTV

Advancements in three dimensional (3D) technologies are rapidly increasing. Three Dimensional Television (3DTV) aims at creating 3D experience for the home user. Moreover, multiview autostereoscopic displays provide a depth impression without the requirement for any special glasses and can be viewed from multiple locations. One of the key issues in the 3DTV processing chain is the content generation from the available input data format video plus depth and multiview video plus depth. This data allows for the possibility of producing virtual views using depth-image-based rendering. Although depth-image-based rendering is an efficient method, it is known for appearance of artifacts such as cracks, corona and empty regions in rendered images. While several approaches have tackled the problem, reducing the artifacts in rendered images is still an active field of research.   Two problems are addressed in this thesis in order to achieve a better 3D video quality in the context of view rendering: firstly, how to improve the quality of rendered views using a direct approach (i.e. without applying specific processing steps for each artifact), and secondly, how to fill the large missing areas in a visually plausible manner using neighbouring details from around the missing regions. This thesis introduces a new depth-image-based rendering and depth-based texture inpainting in order to address these two problems. The first problem is solved by an edge-aided rendering method that relies on the principles of forward warping and one dimensional interpolation. The other problem is addressed by using the depth-included curvature inpainting method that uses appropriate depth level texture details around disocclusions.   The proposed edge-aided rendering method and depth-included curvature inpainting methods are evaluated and compared with the state-of-the-art methods. The results show an increase in the objective quality and the visual gain over reference methods. The quality gain is encouraging as the edge-aided rendering method omits the specific processing steps to remove the rendering artifacts. Moreover, the results show that large disocclusions can be effectively filled using the depth-included curvature inpainting approach. Overall, the proposed approaches improve the content generation for 3DTV and additionally, for free view point television

Free View Rendering for 3D Video : Edge-Aided Rendering and Depth-Based Image Inpainting

Three Dimensional Video (3DV) has become increasingly popular with the success of 3D cinema. Moreover, emerging display technology offers an immersive experience to the viewer without the necessity of any visual aids such as 3D glasses. 3DV applications, Three Dimensional Television (3DTV) and Free Viewpoint Television (FTV) are auspicious technologies for living room environments by providing immersive experience and look around facilities. In order to provide such an experience, these technologies require a number of camera views captured from different viewpoints. However, the capture and transmission of the required number of views is not a feasible solution, and thus view rendering is employed as an efficient solution to produce the necessary number of views. Depth-image-based rendering (DIBR) is a commonly used rendering method. Although DIBR is a simple approach that can produce the desired number of views, inherent artifacts are major issues in the view rendering. Despite much effort to tackle the rendering artifacts over the years, rendered views still contain visible artifacts. This dissertation addresses three problems in order to improve 3DV quality: 1) How to improve the rendered view quality using a direct approach without dealing each artifact specifically. 2) How to handle disocclusions (a.k.a. holes) in the rendered views in a visually plausible manner using inpainting. 3) How to reduce spatial inconsistencies in the rendered view. The first problem is tackled by an edge-aided rendering method that uses a direct approach with one-dimensional interpolation, which is applicable when the virtual camera distance is small. The second problem is addressed by using a depth-based inpainting method in the virtual view, which reconstructs the missing texture with background data at the disocclusions. The third problem is undertaken by a rendering method that firstly inpaint occlusions as a layered depth image (LDI) in the original view, and then renders a spatially consistent virtual view. Objective assessments of proposed methods show improvements over the state-of-the-art rendering methods. Visual inspection shows slight improvements for intermediate views rendered from multiview videos-plus-depth, and the proposed methods outperforms other view rendering methods in the case of rendering from single view video-plus-depth. Results confirm that the proposed methods are capable of reducing rendering artifacts and producing spatially consistent virtual views. In conclusion, the view rendering methods proposed in this dissertation can support the production of high quality virtual views based on a limited number of input views. When used to create a multi-scopic presentation, the outcome of this dissertation can benefit 3DV technologies to improve the immersive experience

Active Noise Control of an Insulated Box Fan using Feedforward and Feedback Control

In recent years, the active noise control methods are more attractive in reducing unwanted noise. Salient features of active control methods over passive control methods drive more attention to active noise control systems for reduction of low frequency noise. The main work in this thesis is active noise reduction of sound in the ventilation systems. Two different kinds of active noise control methods were introduced to reduce the unwanted noise and the implementations were successful. In conclusion, choose the best method based on the best attenuation achievement using different setups of the du

Active Noise Control of an Insulated Box Fan using Feedforward and Feedback Control

In recent years, the active noise control methods are more attractive in reducing unwanted noise. Salient features of active control methods over passive control methods drive more attention to active noise control systems for reduction of low frequency noise. The main work in this thesis is active noise reduction of sound in the ventilation systems. Two different kinds of active noise control methods were introduced to reduce the unwanted noise and the implementations were successful. In conclusion, choose the best method based on the best attenuation achievement using different setups of the du

Spatio-Temporal Consistent Depth-Image Based Rendering Using Layered Depth Image and Inpainting

Depth-image-based rendering (DIBR) is a commonly used method for synthesizing additional views using video-plus-depth (V+D) format. A critical issue with DIBR based view synthesis is the lack of information behind foreground objects. This lack is manifested as disocclusions, holes, next to the foreground objects in rendered virtual views as a consequence of the virtual camera “seeing” behind the foreground object. The disocclusions are larger in the extrapolation case, i.e. the single camera case. Texture synthesis methods (inpainting methods) aim to fill these disocclusions by producing plausible texture content. However, virtual views inevitably exhibit both spatial and temporal inconsistencies at the filled disocclusion areas, depending on the scene content. In this paper we propose a layered depth image (LDI) approach that improves the spatio-temporal consistency. In the process of LDI generation, depth information is used to classify the foreground and background in order to form a static scene sprite from a set of neighboring frames. Occlusions in the LDI are then identified and filled using inpainting, such that no disocclusions appear when the LDI data is rendered to a virtual view. In addition to the depth information, optical flow is computed to extract the stationary parts of the scene and to classify the occlusions in the inpainting process. Experimental results demonstrate that spatio-temporal inconsistencies are significantly reduced using the proposed method. Furthermore, subjective and objective qualities are improved compared to state-of-the-art reference methods

Disocclusion Handling Using Depth-Based Inpainting

Depth image based rendering (DIBR) plays an important role in producing virtual views using 3D-video formats such as video plus depth (V+D) and multi view-videoplus-depth (MVD). Pixel regions with non-defined values (due to disoccluded areas) are exposed when DIBR is used. In this paper, we propose a depth-based inpainting method aimed to handle Disocclusions in DIBR from V+D and MVD. Our proposed method adopts the curvature driven diffusion (CDD) model as a data term, to which we add a depth constraint. In addition, we add depth to further guide a directional priority term in the exemplar based texture synthesis. Finally, we add depth in the patch-matching step to prioritize background texture when inpainting. The proposed method is evaluated by comparing inpainted virtual views with corresponding views produced by three state-of-the-art inpainting methods as references. The evaluation shows the proposed method yielding an increased objective quality compared to the reference methods, and visual inspection further indicate an improved visual quality

Depth-Based Inpainting For Disocclusion Filling

Depth-based inpainting methods can solve disocclusion problems occurring in depth-image-based rendering. However, inpainting in this context suffers from artifacts along foreground objects due to foreground pixels in the patch matching. In this paper, we address the disocclusion problem by a refined depth-based inpainting method. The novelty is in classifying the foreground and background by using available local depth information. Thereby, the foreground information is excluded from both the source region and the target patch. In the proposed inpainting method, the local depth constraints imply inpainting only the background data and preserving the foreground object boundaries. The results from the proposed method are compared with those from the state-of-the art inpainting methods. The experimental results demonstrate improved objective quality and a better visual quality along the object boundaries

Edge-preserving depth-image-based rendering method

Distributionof future 3DTV is likely to use supplementary depth information to a videosequence. New virtual views may then be rendered in order to adjust todifferent 3D displays. All depth-imaged-based rendering (DIBR) methods sufferfrom artifacts in the resulting images, which are corrected by differentpost-processing. The proposed method is based on fundamental principles of3D-warping. The novelty lies in how the virtual view sample values are obtainedfrom one-dimensional interpolation, where edges are preserved by introducing specificedge-pixels with information about both foreground and background data. Thisavoids fully the post-processing of filling cracks and holes. We comparedrendered virtual views of our method and of the View Synthesis ReferenceSoftware (VSRS) and analyzed the results based on typical artifacts. Theproposed method obtained better quality for photographic images and similarquality for synthetic images

Active Noise Control of a Radial Fan

This thesis work aims at investigating the use of an active noise control (ANC) system on a radial fan. This was done by studying the fan structure and its potential working environment (the ducts). This includes measuring the sound levels on several positions and select suitable positions to apply the ANC system. Moreover, the tested ANC system was implemented on the ventilation system and acceptable results were obtained. Further analyses were made based on the obtained results and some explanations were derived to investigate the reason behind the ANC systems incapability to attenuate the noise generated by the fan at some frequencies