{"title":"3D reconstruction of mirror-type objects using efficient ray coding","authors":"S. Tin, Jinwei Ye, M. Nezamabadi, Can Chen","doi":"10.1109/ICCPHOT.2016.7492867","DOIUrl":"https://doi.org/10.1109/ICCPHOT.2016.7492867","url":null,"abstract":"Mirror-type specular objects are difficult to reconstruct: they do not possess their own appearance and the reflections from environment are view-dependent. In this paper, we present a novel computational imaging solution for reconstructing the mirror-type specular objects. Specifically, we adopt a two-layer liquid crystal display (LCD) setup to encode the illumination directions. We devise an efficient ray coding scheme by only considering the useful rays. To recover the mirror-type surface, we derive a normal integration scheme under the perspective camera model. Since the resulting surface is determined up to a scale, we develop a single view approach to resolve the scale ambiguity. To acquire the object surface as completely as possible, we further develop a multiple-surface fusion algorithm to combine the surfaces recovered from different viewpoints. Both synthetic and real experiments demonstrate that our approach is reliable on recovering small to medium scale mirror-type objects.","PeriodicalId":156635,"journal":{"name":"2016 IEEE International Conference on Computational Photography (ICCP)","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116018581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chia-Yin Tsai, A. Veeraraghavan, Aswin C. Sankaranarayanan
{"title":"Shape and reflectance from two-bounce light transients","authors":"Chia-Yin Tsai, A. Veeraraghavan, Aswin C. Sankaranarayanan","doi":"10.1109/ICCPHOT.2016.7492882","DOIUrl":"https://doi.org/10.1109/ICCPHOT.2016.7492882","url":null,"abstract":"Computer vision and image-based inference have predominantly focused on extracting scene information by assuming that the camera measures direct light transport (i.e., single-bounce light paths). As a consequence, strong multi-bounce effects are treated typically as sources of noise and, in many scenarios, the presence of such effects can result in gross errors in the estimates of shape and reflectance. This paper provides the theoretical and algorithmic foundations for shape and reflectance estimation from two-bounce light transients, i.e., scenarios where photons from a light source interact with the scene exactly twice before reaching the sensor We derive sufficient conditions for exact recovery of shape and reflectance given lengths and intensities associated with two-bounce light paths. We also develop algorithms for recovery of shape and reflectance, and validate these on a range of simulated scenes.","PeriodicalId":156635,"journal":{"name":"2016 IEEE International Conference on Computational Photography (ICCP)","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129748432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Teresa Klatzer, K. Hammernik, Patrick Knöbelreiter, T. Pock
{"title":"Learning joint demosaicing and denoising based on sequential energy minimization","authors":"Teresa Klatzer, K. Hammernik, Patrick Knöbelreiter, T. Pock","doi":"10.1109/ICCPHOT.2016.7492871","DOIUrl":"https://doi.org/10.1109/ICCPHOT.2016.7492871","url":null,"abstract":"Demosaicing is an important first step for color image acquisition. For practical reasons, demosaicing algorithms have to be both efficient and yield high quality results in the presence of noise. The demosaicing problem poses several challenges, e.g. zippering and false color artifacts as well as edge blur. In this work, we introduce a novel learning based method that can overcome these challenges. We formulate demosaicing as an image restoration problem and propose to learn efficient regularization inspired by a variational energy minimization framework that can be trained for different sensor layouts. Our algorithm performs joint demosaicing and denoising in close relation to the real physical mosaicing process on a camera sensor. This is achieved by learning a sequence of energy minimization problems composed of a set of RGB filters and corresponding activation functions. We evaluate our algorithm on the Microsoft Demosaicing data set in terms of peak signal to noise ratio (PSNR) and structured similarity index (SSIM). Our algorithm is highly efficient both in image quality and run time. We achieve an improvement of up to 2.6 dB over recent state-of-the-art algorithms.","PeriodicalId":156635,"journal":{"name":"2016 IEEE International Conference on Computational Photography (ICCP)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130692591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Mihara, Takuya Funatomi, Kenichiro Tanaka, Hiroyuki Kubo, Y. Mukaigawa, H. Nagahara
{"title":"4D light field segmentation with spatial and angular consistencies","authors":"H. Mihara, Takuya Funatomi, Kenichiro Tanaka, Hiroyuki Kubo, Y. Mukaigawa, H. Nagahara","doi":"10.1109/ICCPHOT.2016.7492872","DOIUrl":"https://doi.org/10.1109/ICCPHOT.2016.7492872","url":null,"abstract":"In this paper, we describe a supervised four-dimensional (4D) light field segmentation method that uses a graph-cut algorithm. Since 4D light field data has implicit depth information and contains redundancy, it differs from simple 4D hyper-volume. In order to preserve redundancy, we define two neighboring ray types (spatial and angular) in light field data. To obtain higher segmentation accuracy, we also design a learning-based likelihood, called objectness, which utilizes appearance and disparity cues. We show the effectiveness of our method via numerical evaluation and some light field editing applications using both synthetic and real-world light fields.","PeriodicalId":156635,"journal":{"name":"2016 IEEE International Conference on Computational Photography (ICCP)","volume":"214 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130739406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Towards flexible sheet cameras: Deformable lens arrays with intrinsic optical adaptation","authors":"Daniel C. Sims, Yonghao Yue, S. Nayar","doi":"10.1109/ICCPHOT.2016.7492876","DOIUrl":"https://doi.org/10.1109/ICCPHOT.2016.7492876","url":null,"abstract":"We propose a framework for developing a new class of imaging systems that are thin and flexible. Such an imaging sheet can be flexed at will and wrapped around everyday objects to capture unconventional fields of view. Our approach is to use a lens array attached to a sheet with a 2D grid of pixels. A major challenge with this type of a system is that its sampling of the scene varies with the curvature of the sheet. To avoid undesirable aliasing effects due to under-sampling in high curvature regions of the sheet, we design a deformable lens array with adaptive optical properties. We show that the material and geometric properties of the lens array can be optimized so that the object-side point spread function corresponding to each pixel widens with the curvature of the sheet at that pixel. This intrinsic adaptation of focal length is passive (without the use of actuators or other control mechanisms), and enables a sheet camera to capture images without aliasing, irrespective of its shape. We have designed a 33×33 lens array, fabricated it using silicone rubber, and conducted several experiments to verify its optical adaptation characteristics. We conclude with a discussion on the advantages of our proposed approach as well as future work.","PeriodicalId":156635,"journal":{"name":"2016 IEEE International Conference on Computational Photography (ICCP)","volume":"108 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132879782","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ivaylo Boyadzhiev, Jiawen Chen, Sylvain Paris, K. Bala
{"title":"Do-it-yourself lighting design for product videography","authors":"Ivaylo Boyadzhiev, Jiawen Chen, Sylvain Paris, K. Bala","doi":"10.1109/ICCPHOT.2016.7492878","DOIUrl":"https://doi.org/10.1109/ICCPHOT.2016.7492878","url":null,"abstract":"The growth of online marketplaces for selling goods has increased the need for product photography by novice users and consumers. Additionally, the increased use of online media and large-screen billboards promotes the adoption of videos for advertising, going beyond just using still imagery. Lighting is a key distinction between professional and casual product videography. Professionals use specialized hardware setups, and bring expert skills to create good lighting that shows off the product's shape and material, while also producing aesthetically pleasing results. In this paper, we introduce a new do-it-yourself (DIY) approach to lighting design that lets novice users create studio quality product videography. We identify design principles to light products through emphasizing highlights, rim lighting, and contours. We devise a set of computational metrics to achieve these design goals. Our workflow is: the user acquires a video of the product by mounting a video camera on a tripod and using a tablet to light objects by waving the tablet around the object. We automatically analyze and split this acquired video into snippets that match our design principles. Finally, we present an interface that lets users easily select snippets with specific characteristics and then assembles them to produce a final pleasing video of the product. Alternatively, they can rely on our template mechanism to automatically assemble a video.","PeriodicalId":156635,"journal":{"name":"2016 IEEE International Conference on Computational Photography (ICCP)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123833758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vadim Holodovsky, Y. Schechner, Anat Levin, Aviad Levis, Amit Aides
{"title":"In-situ multi-view multi-scattering stochastic tomography","authors":"Vadim Holodovsky, Y. Schechner, Anat Levin, Aviad Levis, Amit Aides","doi":"10.1109/ICCPHOT.2016.7492869","DOIUrl":"https://doi.org/10.1109/ICCPHOT.2016.7492869","url":null,"abstract":"To recover the three dimensional (3D) volumetric matter distribution in an object, the object is imaged from multiple directions and locations. Using these images, tomographic computations seek the distribution. When scattering is significant and under constrained irradiance, tomography must explicitly account for off-axis scattering. Furthermore, tomographic recovery must function when imaging is done in-situ, as occurs in medical imaging and ground-based atmospheric sensing. We formulate tomography that handles arbitrary orders of scattering, using a Monte-Carlo model. The model is highly parallelizable in our formulation. This can enable large scale rendering and recovery of volumetric scenes having a large number of variables. We solve stability and conditioning problems that stem from radiative transfer modeling in-situ.","PeriodicalId":156635,"journal":{"name":"2016 IEEE International Conference on Computational Photography (ICCP)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122438743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}