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A projector is usually coupled with a dedicated projection surface to properly display visual information. This prevents the application of projection in places where a dedicated projection surface is not readily available. This paper presents a method for automatically detecting a good surface in a daily living and working space to support improvisatory projection without a pre-installed projection...
Recovering 3D scene geometry from underwater images involves the Refractive Structure-from-Motion (RSfM) problem, where the image distortions caused by light refraction at the interface between different propagation media invalidates the single view point assumption. Direct use of the pinhole camera model in RSfM leads to inaccurate camera pose estimation and consequently drift. RSfM methods have...
Accurate ground area detection is one of the most important tasks in various stereo vision based applications, such as autonomous driving or assistive technologies for visually impaired. Correct assertion of the ground geometry improves obstacle detection algorithms by eliminating false positive locations in image. In this paper we provide an application oriented evaluation on the correlation of the...
Traversable region estimation is the fundamental enabler in autonomous navigation. In this paper, we propose a traversable region segmentation algorithm using stereo vision. We address this problem mainly in road scenes for the goal of autonomous driving. Using only geometry information, our approach has the advantages of effectiveness and robustness. The proposed approach is based on a cascaded framework...
A vast majority of consumer cameras operate the rolling shutter mechanism, which often produces distorted images due to inter-row delay while capturing an image. Recent methods for monocular rolling shutter compensation utilize blur kernel, straightness of line segments, as well as angle and length preservation. However, they do not incorporate scene geometry explicitly for rolling shutter correction,...
This paper presents an extension of block-based motion estimation for omnidirectional videos, based on a translational object motion model that accounts for the spherical geometry of the imaging system. We use this model to design a new algorithm to perform block matching in sequences of panoramic frames that are the result of the equirectangular projection. Experimental results demonstrate that significant...
This paper describes an industrial close-range photogrammetric system that is being developed by the authors. We describe the system's architecture based on an iterative scheme, which allows using fast heuristic point matching algorithms with the follow-up result verification. We also describe the design of our multi-functional coded targets that allow using those algorithms. Besides, this design...
Calibration of multi-projector-camera systems (MPCS) is a cumbersome and time-consuming process. It is of great importance to have robust, fast and accurate calibration procedures at hand for a wide variety of practical applications. We propose a fully automated self-calibration method for arbitrarily complex MPCS. It enables reliable and accurate intrinsic and extrinsic calibration without any human...
Drones equipped with cameras are emerging as a powerful tool for large-scale aerial 3D scanning, but existing automatic flight planners do not exploit all available information about the scene, and can therefore produce inaccurate and incomplete 3D models. We present an automatic method to generate drone trajectories, such that the imagery acquired during the flight will later produce a high-fidelity...
Parsing urban scene images benefits many applications, especially self-driving. Most of the current solutions employ generic image parsing models that treat all scales and locations in the images equally and do not consider the geometry property of car-captured urban scene images. Thus, they suffer from heterogeneous object scales caused by perspective projection of cameras on actual scenes and inevitably...
Finding a closed form solution to a system of polynomial equations is a common problem in computer vision as well as in many other areas of engineering and science. Gröb-ner basis techniques are often employed to provide the solution, but implementing an efficient Gröbner basis solver to a given problem requires strong expertise in algebraic geometry. One can also convert the equations to a polynomial...
We address the problem of epipolar geometry using the motion of silhouettes. Such methods match epipolar lines or frontier points across views, which are then used as the set of putative correspondences. We introduce an approach that improves by two orders of magnitude the performance over state-of-the-art methods, by significantly reducing the number of outliers in the putative matching. We model...
Traditional Structure-from-Motion (SfM) uses images captured by cameras as inputs. In this paper, we explore using light fields captured by plenoptic cameras or camera arrays as inputs. We call this solution plenoptic SfM or P-SfM solution. We first present a comprehensive theory on ray geometry transforms under light field pose variations. We derive the transforms of three typical ray manifolds:...
How much does a single image reveal about the environment it was taken in? In this paper, we investigate how much of that information can be retrieved from a foreground object, combined with the background (i.e. the visible part of the environment). Assuming it is not perfectly diffuse, the foreground object acts as a complexly shaped andfar-from-perfect mirror An additional challenge is that its...
We introduce a novel method to obtain high-quality 3D reconstructions from consumer RGB-D sensors. Our core idea is to simultaneously optimize for geometry encoded in a signed distance field (SDF), textures from automatically-selected keyframes, and their camera poses along with material and scene lighting. To this end, we propose a joint surface reconstruction approach that is based on Shape-from-Shading...
Two types of information exist in a stereo pair: correlation (matching) and decorrelation (half-occlusion). Vision science has shown that both types of information are used in the visual cortex, and that people can perceive depth even when correlation cues are absent or very weak, a capability that remains absent from most computational stereo systems. As a step toward stereo algorithms that are more...
The paper is devoted to the problem of automatic geometry evaluation of the log moving through the conveyor. The video sequence obtained from the single camera is used as the input data. The principal restrictions of the target objects described for the given task, and the requirements to the video recording of the manufacturing process are formulated on the basis of datasets from more than .5M video...
A video is a temporally ordered sequence of images. Videos capture appearance from a fixed set of viewpoints, that is where the camera is placed during recording (acquisition). A light field generalizes this idea, by encoding enough information in the recorded data that pictures may be rendered from arbitrarily chosen viewpoints. Typically, light fields are recorded by using several pictures of the...
The state of the art VR/AR devices provide access to completely virtual environments or augment information on the existing world seen by the user. Wearable devices encumber the users, and sometimes even cut them off completely from the real world. Users interact with digital avatars instead of the real people themselves. Spatially augmented reality (SAR) instead focuses on illuminating physical spaces...
The rational camera model recently introduced in [18] provides a general methodology for studying abstract nonlinear imaging systems and their multi-view geometry. This paper builds on this framework to study physical realizations of rational cameras. More precisely, we give an explicit account of the mapping between between physical visual rays and image points (missing in the original description),...
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