DOCSLIB.ORG

Stereo Depth Map Fusion for Robot Navigation

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Stereo Depth Map Fusion for Robot Navigation Stereo Depth Map Fusion for Robot Navigation Christian Hane¨ 1, Christopher Zach1, Jongwoo Lim2, Ananth Ranganathan2 and Marc Pollefeys1 Department of Computer Science1 Honda Research Institute2 ETH Zurich,¨ Switzerland Mountain View, CA, USA Abstract— We present a method to reconstruct indoor envi- In order to overcome this problem we combine several ronments from stereo image pairs, suitable for the navigation depth maps calculated from multiple stereo images into of robots. To enable a robot to navigate solely using visual a common representation. Thus, inconsistencies between cues it receives from a stereo camera, the depth information needs to be extracted from the image pairs and combined several acquired depth maps can be discovered and removed. into a common representation. The initially determined raw We propose to use a height map based representation of the depthmaps are fused into a two level heightmap representation environment for the globally combined representation of the which contains a floor and a ceiling height level. To reduce the scene. For indoor environments the height map is composed noise in the height maps we employ a total variation regularized of two levels, a floor and a ceiling level. energy functional. With this 2.5D representation of the scene the computational complexity of the energy optimization is reduced Our target setting is a humanoid robot that is equipped by one dimension in contrast to other fusion techniques that with a stereo camera, which enables it to observe its sur- work on the full 3D space such as volumetric fusion. While we roundings. The two cameras are mounted on a stereo rig show only results for indoor environments the approach can be with fixed relative position. It is further assumed that the extended to generate heightmaps for outdoor environments. intrinsic calibration of the two cameras are known. For the fusion procedure the camera poses are needed as well. For I. INTRODUCTION this we use the output of existing VSLAM pipelines. To enable a robot to navigate with visual data captured The remainder of the paper is structured as follows. In from a stereo camera it needs to be able to have some section II prior work related to this paper is presented. Our kind of representation of the observed world that is suitable height map based reconstruction approach is explained in for this task. There is a large literature on visual simul- section III. In section IV we show the results we obtained taneous localization and mapping (VSLAM) generating a for indoor environments and compare them to a full 3D re- sparse representation of the environment and the respective construction of the scene. Finally we draw some conclusions camera/robot poses. However such a sparse representation in section V. generally only includes points that are salient enough in the considered images and thus lie in well textured regions. For II. RELATED WORK instance, uniformely painted walls and homogeneous regions There exists a vast literature on computational stereo, in general are not covered by the model obtained from fusion of range data, and general 3D modeling from images. VSLAM and therefore problematic for robot navigation. We focus on approaches suitable for efficient implementation The representation of the robot’s surroundings needs to or explicitly addressing reconstruction of indoor environ- be appropriate for higher-level tasks such as path planning ments. Merell et al. [1] propose a visibility-based approach and collision avoidance. Although one could use the re- capable of real-time operation to fuse a sequence of nearby constructed sparse feature points from a VSLAM pipeline depthmaps to a single depthmap with a higher confidence. directly for collision avoidance, this can potentially miss This is done by projecting the depthmaps to a reference view whole objects that lack some feature points. In such a case and then choose one of the depths projecting to the same the possible obstacle would just be invisible for the robot. In position that reduces the number of visibility conflicts. A indoor environments such objects are quite common e.g. a visibility conflict is the situation where a measurement lies uniformly colored wall. Thus a denser representation of the in the free space of some other measurement. While this scene is favorable. gives more accurate depthmaps, which could be certainly Many local and global stereo methods are available to used for collision avoidance there is no direct way to generate determine depth from images, but the returned depth maps a globally consistent representation of the complete observed are generally still contaminated by inaccurate and erroneous space. Because there is no regularization used in this fusion depth estimates. This problems emerge especially in texture- the resulting depthmaps also still contain some noise. less parts of images, which are quite common in indoor In order to obtain globally consistent 3D models from environments. Although global stereo methods optimize an a set of range images Zach et al. [2], [3] use an implicit energy functional over the whole image domain in order to representation of the space. The input depthmaps are con- hypothesize reasonable depth values in ambiguous regions, verted to signed distance fields. A total variation energy the resulting depth maps may still contain errors. functional with a L1 distance data fidelity term, is defined on a regularized signed distance field that simultaneously ap- proximates all the input fields. This convex energy functional is minimized to get the final reconstructed scene. In [4] Furukawa et al. use the Manhattan world assump- tion, which means that all the surfaces are oriented according to the coordinate axes, to formulate a stereo algorithm that is able to handle flat textureless surfaces. From the directions obtained by the patch-based multi view stereo (PMVS) software [5], which extracts a semi-dense oriented point cloud from a set of input images with known camera ori- entations, the three orthogonal main directions are extracted. Fig. 1. Two level height map, the floor and the ceiling are approximated by a height level. Afterwards the problem of assigning a plane to each of the pixels is formulated as a Markov random field (MRF) and solved using the graph cut method. This finally leads to a According to this considerations it makes sense to constrain depthmap that contains flat surfaces oriented according to the final reconstruction to be represented by a floor and the three main directions. In [6] they use this depthmaps ceiling height level (Fig. 1). to reconstruct building interiors. In a similar way as in [2], [3] they integrate the depth maps to a volumetric structure. A. Depth Integration Here the voxels have a binary label interior or exterior. To As first step the raw depthmaps are integrated into a vol- get a full labeling of the space that best approximates all umetric representation of the space. This is done by creating the given input depthmaps a MRF is formulated and solved an occupancy grid that stores a negative number for free using graph cuts. This leads to complete polygonal meshes space and a positive one for occupied space. With increasing of building interiors but comes with a high computational absolute value the decision for free or occupied space gets cost: reported run-times range from a few hours to multiple more certain. This is similar to the probabilistic formulation days. of occupancy grids e.g. [9]. The z-axis is aligned with the Gallup et al. [7], [8] use a height map representation upright direction of the scene such that the discontinuities to reconstruct urban environments. They integrate the raw in the height map are vertical walls. We detect the upright depth maps to a three dimensional occupancy grid, which is direction in the input images by detecting the associated aligned such that the z-axis points to the upright direction. vanishing point. For each voxel a number is stored, free space gets a negative In order to integrate a new depthmap to the common weight and occupied space a positive weight. The space in volumetric representation, each voxel is projected onto the front of the measured depth is assumed to be free and the new depthmap. For every voxel v the weight that it adds to space behind the measurement is expected to be occupied the grid is calculated. It is dependent on the depth zv that with an exponential drop of the weight. One or multiple the voxel v has according to the new view and on the depth height levels are then extracted by getting the minimum measurement zp of the depthpixel p to which v projects. Due of an energy functional for each z-column. Because each to the constant disparity resolution in the stereo image the column is optimized independently, this can be calculated depth resolution is decreasing with increasing depth [10]. very efficiently by GPUs, but has the drawback that there is To include this into our cost function a band around the no regularization between the columns. measurement whose width is dependent on the measured In this work we focus on representing indoor environments depth zp is defined. The width of the band is given by, by two level height maps. But in contrast to [7], [8] we use a ( ) total variation energy functional to obtain regularized results. z2 l (z ) = max p δ ;" : (1) This leads to reconstructions where most of of the noise is p p bf d removed. It has the benefit over full 3D reconstructions like the one in [2], [3] that it can be computed faster due to the The first operand approximates the depth uncertainty [10], reduced representation, which is still able to represent the where δd is the disparity resolution, b the stereo rig base scene accurately enough to be used for robot navigation.
Load more

Recommended publications
  • Interacting with Autostereograms
    See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/336204498 Interacting with Autostereograms Conference Paper · October 2019 DOI: 10.1145/3338286.3340141 CITATIONS READS 0 39 5 authors, including: William Delamare Pourang Irani Kochi University of Technology University of Manitoba 14 PUBLICATIONS 55 CITATIONS 184 PUBLICATIONS 2,641 CITATIONS SEE PROFILE SEE PROFILE Xiangshi Ren Kochi University of Technology 182 PUBLICATIONS 1,280 CITATIONS SEE PROFILE Some of the authors of this publication are also working on these related projects: Color Perception in Augmented Reality HMDs View project Collaboration Meets Interactive Spaces: A Springer Book View project All content following this page was uploaded by William Delamare on 21 October 2019. The user has requested enhancement of the downloaded file. Interacting with Autostereograms William Delamare∗ Junhyeok Kim Kochi University of Technology University of Waterloo Kochi, Japan Ontario, Canada University of Manitoba University of Manitoba Winnipeg, Canada Winnipeg, Canada [email protected] [email protected] Daichi Harada Pourang Irani Xiangshi Ren Kochi University of Technology University of Manitoba Kochi University of Technology Kochi, Japan Winnipeg, Canada Kochi, Japan [email protected] [email protected] [email protected] Figure 1: Illustrative examples using autostereograms. a) Password input. b) Wearable e-mail notification. c) Private space in collaborative conditions. d) 3D video game. e) Bar gamified special menu. Black elements represent the hidden 3D scene content. ABSTRACT practice. This learning effect transfers across display devices Autostereograms are 2D images that can reveal 3D content (smartphone to desktop screen). when viewed with a specific eye convergence, without using CCS CONCEPTS extra-apparatus.
    [Show full text]
  • A Residual Network and FPGA Based Real-Time Depth Map Enhancement System
    entropy Article A Residual Network and FPGA Based Real-Time Depth Map Enhancement System Zhenni Li 1, Haoyi Sun 1, Yuliang Gao 2 and Jiao Wang 1,* 1 College of Information Science and Engineering, Northeastern University, Shenyang 110819, China; [email protected] (Z.L.); [email protected] (H.S.) 2 College of Artificial Intelligence, Nankai University, Tianjin 300071, China; [email protected] * Correspondence: [email protected] Abstract: Depth maps obtained through sensors are often unsatisfactory because of their low- resolution and noise interference. In this paper, we propose a real-time depth map enhancement system based on a residual network which uses dual channels to process depth maps and intensity maps respectively and cancels the preprocessing process, and the algorithm proposed can achieve real- time processing speed at more than 30 fps. Furthermore, the FPGA design and implementation for depth sensing is also introduced. In this FPGA design, intensity image and depth image are captured by the dual-camera synchronous acquisition system as the input of neural network. Experiments on various depth map restoration shows our algorithms has better performance than existing LRMC, DE-CNN and DDTF algorithms on standard datasets and has a better depth map super-resolution, and our FPGA completed the test of the system to ensure that the data throughput of the USB 3.0 interface of the acquisition system is stable at 226 Mbps, and support dual-camera to work at full speed, that is, 54 fps@ (1280 × 960 + 328 × 248 × 3). Citation: Li, Z.; Sun, H.; Gao, Y.; Keywords: depth map enhancement; residual network; FPGA; ToF Wang, J.
    [Show full text]
  • Deep Learning Whole Body Point Cloud Scans from a Single Depth Map
    Deep Learning Whole Body Point Cloud Scans from a Single Depth Map Nolan Lunscher John Zelek University of Waterloo University of Waterloo 200 University Ave W. 200 University Ave W. [email protected] [email protected] Abstract ture the complete 3D structure of an object or person with- out the need for the machine or operator to necessarily be Personalized knowledge about body shape has numerous an expert at how to take every measurement. Scanning also applications in fashion and clothing, as well as in health has the benefit that all possible measurements are captured, monitoring. Whole body 3D scanning presents a relatively rather than only measurements at specific points [27]. simple mechanism for individuals to obtain this information Beyond clothing, understanding body measurements and about themselves without needing much knowledge of an- shape can provide details about general health and fitness. thropometry. With current implementations however, scan- In recent years, products such as Naked1 and ShapeScale2 ning devices are large, complex and expensive. In order to have begun to be released with the intention of capturing 3D make such systems as accessible and widespread as pos- information about a person, and calculating various mea- sible, it is necessary to simplify the process and reduce sures such as body fat percentage and muscle gains. The their hardware requirements. Deep learning models have technologies can then be used to monitor how your body emerged as the leading method of tackling visual tasks, in- changes overtime, and offer detailed fitness tracking. cluding various aspects of 3D reconstruction. In this paper Depth map cameras and RGBD cameras, such as the we demonstrate that by leveraging deep learning it is pos- XBox Kinect or Intel Realsense, have become increasingly sible to create very simple whole body scanners that only popular in 3D scanning in recent years, and have even made require a single input depth map to operate.
    [Show full text]
  • Fusing Multimedia Data Into Dynamic Virtual Environments
    ABSTRACT Title of dissertation: FUSING MULTIMEDIA DATA INTO DYNAMIC VIRTUAL ENVIRONMENTS Ruofei Du Doctor of Philosophy, 2018 Dissertation directed by: Professor Amitabh Varshney Department of Computer Science In spite of the dramatic growth of virtual and augmented reality (VR and AR) technology, content creation for immersive and dynamic virtual environments remains a signifcant challenge. In this dissertation, we present our research in fusing multimedia data, including text, photos, panoramas, and multi-view videos, to create rich and compelling virtual environments. First, we present Social Street View, which renders geo-tagged social media in its natural geo-spatial context provided by 360° panoramas. Our system takes into account visual saliency and uses maximal Poisson-disc placement with spatiotem- poral flters to render social multimedia in an immersive setting. We also present a novel GPU-driven pipeline for saliency computation in 360° panoramas using spher- ical harmonics (SH). Our spherical residual model can be applied to virtual cine- matography in 360° videos. We further present Geollery, a mixed-reality platform to render an interactive mirrored world in real time with three-dimensional (3D) buildings, user-generated content, and geo-tagged social media. Our user study has identifed several use cases for these systems, including immersive social storytelling, experiencing the culture, and crowd-sourced tourism. We next present Video Fields, a web-based interactive system to create, cal- ibrate, and render dynamic videos overlaid on 3D scenes. Our system renders dynamic entities from multiple videos, using early and deferred texture sampling. Video Fields can be used for immersive surveillance in virtual environments. Fur- thermore, we present VRSurus and ARCrypt projects to explore the applications of gestures recognition, haptic feedback, and visual cryptography for virtual and augmented reality.
    [Show full text]
  • Construction of Autostereograms Taking Into Account Object Colors and Its Applications for Steganography
    Construction of Autostereograms Taking into Account Object Colors and its Applications for Steganography Yusuke Tsuda Yonghao Yue Tomoyuki Nishita The University of Tokyo ftsuday,yonghao,[email protected] Abstract Information on appearances of three-dimensional ob- jects are transmitted via the Internet, and displaying objects q plays an important role in a lot of areas such as movies and video games. An autostereogram is one of the ways to represent three- dimensional objects taking advantage of binocular paral- (a) SS-relation (b) OS-relation lax, by which depths of objects are perceived. In previous Figure 1. Relations on an autostereogram. methods, the colors of objects were ignored when construct- E and E indicate left and right eyes, re- ing autostereogram images. In this paper, we propose a L R spectively. (a): A pair of points on the screen method to construct autostereogram images taking into ac- and a single point on the object correspond count color variation of objects, such as shading. with each other. (b): A pair of points on the We also propose a technique to embed color informa- object and a single point on the screen cor- tion in autostereogram images. Using our technique, au- respond with each other. tostereogram images shown on a display change, and view- ers can enjoy perceiving three-dimensional object and its colors in two stages. Color information is embedded in we propose an approach to take into account color variation a monochrome autostereogram image, and colors appear of objects, such as shading. Our approach assign slightly when the correct color table is used.
    [Show full text]
  • Ddrnet: Depth Map Denoising and Refinement for Consumer Depth
    DDRNet: Depth Map Denoising and Refinement for Consumer Depth Cameras Using Cascaded CNNs Shi Yan1, Chenglei Wu2, Lizhen Wang1, Feng Xu1, Liang An1, Kaiwen Guo3, and Yebin Liu1 1 Tsinghua University, Beijing, China 2 Facebook Reality Labs, Pittsburgh, USA 3 Google Inc, Mountain View, CA, USA Abstract. Consumer depth sensors are more and more popular and come to our daily lives marked by its recent integration in the latest Iphone X. However, they still suffer from heavy noises which limit their applications. Although plenty of progresses have been made to reduce the noises and boost geometric details, due to the inherent illness and the real-time requirement, the problem is still far from been solved. We pro- pose a cascaded Depth Denoising and Refinement Network (DDRNet) to tackle this problem by leveraging the multi-frame fused geometry and the accompanying high quality color image through a joint training strategy. The rendering equation is exploited in our network in an unsupervised manner. In detail, we impose an unsupervised loss based on the light transport to extract the high-frequency geometry. Experimental results indicate that our network achieves real-time single depth enhancemen- t on various categories of scenes. Thanks to the well decoupling of the low and high frequency information in the cascaded network, we achieve superior performance over the state-of-the-art techniques. Keywords: Depth enhancement · Consumer depth camera · Unsuper- vised learning · Convolutional Neural Networks· DynamicFusion 1 Introduction Consumer depth cameras have enabled lots of new applications in computer vision and graphics, ranging from live 3D scanning to virtual and augmented reality.
    [Show full text]
  • Depth Map Design and Depth-Based Effects with a Single Image
    Depth Map Design and Depth-based Effects With a Single Image Jingtang Liao∗ Shuheng Shen† Elmar Eisemann‡ Delft University of Technology ABSTRACT When several views are available, image-based view interpola- We present a novel pipeline to generate a depth map from a single tion [24] is more general. The perceived motion of the objects helps image that can be used as input for a variety of artistic depth-based in estimating spatial relationships. Nonetheless, these techniques effects. In such a context, the depth maps do not have to be perfect often require a special acquisition setup or a carefully produced but are rather designed with respect to a desired result. Consequently, input. Wiggle stereoscopy can be seen as a particular case of view our solution centers around user interaction and relies on a scribble- interpolation, which simply loops left and right images of a stereo based depth editing. The annotations can be sparse, as the depth pair and can result in a striking parallax perception despite its sim- map is generated by a diffusion process, which is guided by image plicity (Fig. 2). These techniques all avoid special equipment, e.g., features. Additionally, we support a variety of controls, such as a 3D glasses, and they even work for people with limited or no vision non-linear depth mapping, a steering mechanism for the diffusion in one eye. (e.g., directionality, emphasis, or reduction of the influence of image Alternatively, it is possible to use a single input image and warp cues), and besides absolute, we also support relative depth indica- it based on a depth map to produce stereo pairs.
    [Show full text]
  • Stereoscopic Depth Map Estimation and Coding Techniques for Multiview Video Systems
    Poznań University of Technology Faculty of Electronics and Telecommunications Chair of Multimedia Telecommunication and Microelectronics Doctoral Dissertation Stereoscopic depth map estimation and coding techniques for multiview video systems Olgierd Stankiewicz Supervisor: Prof. dr hab. inż. Marek Domański POZNAN UNIVERSITY OF TECHNOLOGY Faculty of Electronics and Telecommunications Chair of Multimedia Telecommunications and Microelectronics Pl. M. Skłodowskiej-Curie 5 60-965 Poznań www.multimedia.edu.pl This dissertation was supported by the public funds as a research project. A part of this dissertation related to depth estimation was partially supported by National Science Centre, Poland, according to the decision DEC-2012/07/N/ST6/02267. A part of this dissertation related to depth coding was partially supported by National Science Centre, Poland, according to the decision DEC-2012/05/B/ST7/01279. This dissertation has been partially co-financed by European Union funds as a part of European Social Funds. Copyright © Olgierd Stankiewicz, 2013 All rights reserved Online edition 1, 2015 ISBN 978-83-942477-0-6 This dissertation is dedicated to my beloved parents: Zdzisława and Jerzy, who gave me wonderful childhood and all opportunities for development and fulfillment in life. I would like to thank all important people in my life, who have always been in the right place and supported me in difficult moments, especially during realization of this work. I would like to express special thanks and appreciation to professor Marek Domański, for his time, help and ideas that have guided me towards completing this dissertation. Rozprawa ta dedykowana jest moim ukochanym rodzicom: Zdzisławie i Jerzemu, którzy dali mi cudowne dzieciństwo oraz wszelkie możliwości rozwoju i spełnienia życiowego.
    [Show full text]
  • Towards a Smart Drone Cinematographer for Filming Human Motion
    University of California Santa Barbara Towards a Smart Drone Cinematographer for Filming Human Motion A dissertation submitted in partial satisfaction of the requirements for the degree Doctor of Philosophy in Electrical and Computer Engineering by Chong Huang Committee in charge: Professor Kwang-Ting (Tim) Cheng, Chair Professor Matthew Turk Professor B.S. Manjunath Professor Xin Yang March 2020 The Dissertation of Chong Huang is approved. Professor Matthew Turk Professor B.S. Manjunath Professor Xin Yang Professor Kwang-Ting (Tim) Cheng, Committee Chair March 2020 Towards a Smart Drone Cinematographer for Filming Human Motion Copyright c 2020 by Chong Huang iii I dedicate this dissertation to Avery Huang, whose sweetness encouraged and supported me. iv Acknowledgements I would like to express my sincere gratitude to Professor Tim Cheng for being an excellent advisor, mentor, and collaborator while I have been at UCSB. His guidance helped me to develop my critical thinking. His professional attitude, vision, flexibility and constant encouragement have deeply inspired me. It was a great privilege and honor to work and study under his guidance. I could not have imagined having a better advisor and mentor for my Ph.D study. Besides, I would like to thank Professor Xin Yang for the continuous support of my Ph.D study and research, for her patience, motivation, enthusiasm and immense knowledge. Her guidance helped me in all the time of research and writing of this thesis. I would also like to thank Professor Mathew Turk and B.S. Manjunath, for their interest in my research and sharing with me their expertise and visions in several different fields.
    [Show full text]
  • 3D Reconstruction and Rendering from Image Sequences
    3D Reconstruction and Rendering from Image Sequences R. Koch, J.-F. Evers-Senne, J.-M. Frahm, K. Koeser Institute of Computer Science and Applied Mathematics Christian-Albrechts-University of Kiel, 24098 Kiel, Germany email: [email protected] Abstract For this, the topology problem must be solved to distinguish between connected and occluded surfaces from all views. This contribution describes a system for 3D surface re- Another way would be to render directly from the real views construction and novel view synthesis from image streams using depth-compensated warping [2]. In this case, local of an unknown but static scene. The system operates fully surface geometry between adjacent views is sufficient. In automatic and estimates camera pose and 3D scene geom- our contribution we describe ways to render interpolated etry using Structure-from-Motion and dense multi-camera views using view-dependent geometry and texture models stereo reconstruction. From these estimates, novel views of (VDGT) [3]. the scene can be rendered at interactive rates. We will describe the system and its components in the following section, followed by some experiments and eval- 1 INTRODUCTION uation of the approach. Image Based Rendering (IBR) is an active research field 2 SYSTEM OVERVIEW in the computer vision and graphics community. In the last decade, many systems were proposed that synthesize novel Figure 1 gives an overview on the components of the sys- views based on collections of real views of a scene. Those tem. The complete system can be divided into an offline systems differ with respect to the amount of interactivity for data acquisition and an online rendering part.
    [Show full text]
  • Real-Time Height Map Fusion Using Differentiable Rendering
    Real-Time Height Map Fusion using Differentiable Rendering Jacek Zienkiewicz, Andrew Davison and Stefan Leutenegger Imperial College London, UK Abstract— We present a robust real-time method which performs dense reconstruction of high quality height maps from monocular video. By representing the height map as a triangular mesh, and using efficient differentiable rendering approach, our method enables rigorous incremental probabilis- tic fusion of standard locally estimated depth and colour into an immediately usable dense model. We present results for the application of free space and obstacle mapping by a low- cost robot, showing that detailed maps suitable for autonomous navigation can be obtained using only a single forward-looking camera. I. INTRODUCTION Advancing commodity processing power, particularly from GPUs, has enabled various recent demonstrations of real-time dense reconstruction from monocular video. Usu- ally the approach has been to concentrate on high quality Fig. 1: Left: an example input monocular RGB image and multi-view depth map reconstruction, and then fusion into motion stereo depth map which are inputs to our fusion a generic 3D representation such as a TSDF, surfel cloud algorithm. Right: output RGB and depth image from dif- or mesh. Some of the systems presented in this vein have ferentiable renderer. been impressive, but we note that there are few examples of moving beyond showing real-time dense reconstruction towards using it, in-the-loop, in applications. The live recon- structions are often in a form which needs substantial further processing before they could be useful for any in-the-loop Our core representation for reconstruction is a coloured use such as path planning or scene labelling.
    [Show full text]
  • Single-Shot 3D Shape Reconstruction Using Structured Light and Deep Convolutional Neural Networks
    sensors Article Single-Shot 3D Shape Reconstruction Using Structured Light and Deep Convolutional Neural Networks Hieu Nguyen 1,2 , Yuzeng Wang 3 and Zhaoyang Wang 1,* 1 Department of Mechanical Engineering, The Catholic University of America, Washington, DC 20064, USA 2 Neuroimaging Research Branch, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD 21224, USA; [email protected] 3 School of Mechanical Engineering, Jinan University, Jinan 250022, China; [email protected] * Correspondence: [email protected]; Tel.: +1-202-319-6175 Received: 4 June 2020; Accepted: 30 June 2020; Published: 3 July 2020 Abstract: Single-shot 3D imaging and shape reconstruction has seen a surge of interest due to the ever-increasing evolution in sensing technologies. In this paper, a robust single-shot 3D shape reconstruction technique integrating the structured light technique with the deep convolutional neural networks (CNNs) is proposed. The input of the technique is a single fringe-pattern image, and the output is the corresponding depth map for 3D shape reconstruction. The essential training and validation datasets with high-quality 3D ground-truth labels are prepared by using a multi-frequency fringe projection profilometry technique. Unlike the conventional 3D shape reconstruction methods which involve complex algorithms and intensive computation to determine phase distributions or pixel disparities as well as depth map, the proposed approach uses an end-to-end network architecture to directly carry out the transformation of a 2D image to its corresponding 3D depth map without extra processing. In the approach, three CNN-based models are adopted for comparison. Furthermore, an accurate structured-light-based 3D imaging dataset used in this paper is made publicly available.
    [Show full text]