{"title":"Rolling shutter imaging on the electric grid","authors":"Mark Sheinin, Y. Schechner, Kiriakos N. Kutulakos","doi":"10.1109/ICCPHOT.2018.8368472","DOIUrl":"https://doi.org/10.1109/ICCPHOT.2018.8368472","url":null,"abstract":"Flicker of AC-powered lights is useful for probing the electric grid and unmixing reflected contributions of different sources. Flicker has been sensed in great detail with a specially-designed camera tethered to an AC outlet. We argue that even an untethered smartphone can achieve the same task. We exploit the inter-row exposure delay of the ubiquitous rolling-shutter sensor. When pixel exposure time is kept short, this delay creates a spatiotemporal wave pattern that encodes (1) the precise capture time relative to the AC, (2) the response function of individual bulbs, and (3) the AC phase that powers them. To sense point sources, we induce the spatiotemporal wave pattern by placing a star filter or a paper diffuser in front of the camera's lens. We demonstrate several new capabilities, including: high-rate acquisition of bulb response functions from one smartphone photo; recognition of bulb type and phase from one or two images; and rendering of live flicker video, as if it came from a high speed global-shutter camera.","PeriodicalId":413914,"journal":{"name":"2018 IEEE International Conference on Computational Photography (ICCP)","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115869504","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}
Tomohiro Maeda, A. Kadambi, Y. Schechner, R. Raskar
{"title":"Dynamic heterodyne interferometry","authors":"Tomohiro Maeda, A. Kadambi, Y. Schechner, R. Raskar","doi":"10.1109/ICCPHOT.2018.8368471","DOIUrl":"https://doi.org/10.1109/ICCPHOT.2018.8368471","url":null,"abstract":"Dynamic interferometry enables snapshot recovery of phase images by using polarization phase shifting. However, the phase estimate is susceptible to influence from sources of ambient light having uncontrolled polarization. We present a novel method, dynamic heterodyne interferometry (DHI), as a means to mitigate phase bias from ambient light sources, while retaining dynamic potential.","PeriodicalId":413914,"journal":{"name":"2018 IEEE International Conference on Computational Photography (ICCP)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128212064","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":"Learning to see through reflections","authors":"Meiguang Jin, S. Süsstrunk, P. Favaro","doi":"10.1109/ICCPHOT.2018.8368464","DOIUrl":"https://doi.org/10.1109/ICCPHOT.2018.8368464","url":null,"abstract":"Pictures of objects behind a glass are difficult to interpret and understand due to the superposition of two real images: a reflection layer and a background layer. Separation of these two layers is challenging due to the ambiguities in assigning texture patterns and the average color in the input image to one of the two layers. In this paper, we propose a novel method to reconstruct these layers given a single input image by explicitly handling the ambiguities of the reconstruction. Our approach combines the ability of neural networks to build image priors on large image regions with an image model that accounts for the brightness ambiguity and saturation. We find that our solution generalizes to real images even in the presence of strong reflections. Extensive quantitative and qualitative experimental evaluations on both real and synthetic data show the benefits of our approach over prior work. Moreover, our proposed neural network is computationally and memory efficient.","PeriodicalId":413914,"journal":{"name":"2018 IEEE International Conference on Computational Photography (ICCP)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132049985","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}
Hiroyuki Kubo, Suren Jayasuriya, Takafumi Iwaguchi, Takuya Funatomi, Y. Mukaigawa, S. Narasimhan
{"title":"Acquiring and characterizing plane-to-ray indirect light transport","authors":"Hiroyuki Kubo, Suren Jayasuriya, Takafumi Iwaguchi, Takuya Funatomi, Y. Mukaigawa, S. Narasimhan","doi":"10.1109/ICCPHOT.2018.8368461","DOIUrl":"https://doi.org/10.1109/ICCPHOT.2018.8368461","url":null,"abstract":"Separation of light transport into direct and indirect paths has enabled new visualizations of light in everyday scenes. However, indirect light itself contains a variety of components from subsurface scattering to diffuse and specular interreflections, all of which contribute to complex visual appearance. In this paper, we present a new imaging technique that captures and analyzes these components of indirect light via light transport between epipolar planes of illumination and rays of received light. This plane-to-ray light transport is captured using a rectified projector-camera system where we vary the offset between projector and camera rows (implemented as synchronization delay) as well as the exposure of each camera row. The resulting delay-exposure stack of images can capture live short and long-range indirect light transport, disambiguate subsurface scattering, diffuse and specular interreflections, and distinguish materials according to their subsurface scattering properties.","PeriodicalId":413914,"journal":{"name":"2018 IEEE International Conference on Computational Photography (ICCP)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131340688","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}
Yifan Peng, Xiong Dun, Qilin Sun, Felix Heide, W. Heidrich
{"title":"Focal sweep imaging with multi-focal diffractive optics","authors":"Yifan Peng, Xiong Dun, Qilin Sun, Felix Heide, W. Heidrich","doi":"10.1109/ICCPHOT.2018.8368469","DOIUrl":"https://doi.org/10.1109/ICCPHOT.2018.8368469","url":null,"abstract":"Depth-dependent defocus results in a limited depth-of-field in consumer-level cameras. Computational imaging provides alternative solutions to resolve all-in-focus images with the assistance of designed optics and algorithms. In this work, we extend the concept of focal sweep from refractive optics to diffractive optics, where we fuse multiple focal powers onto one single element. In contrast to state-of-the-art sweep models, ours can generate better-conditioned point spread function (PSF) distributions along the expected depth range with drastically shortened (40%) sweep distance. Further by encoding axially asymmetric PSFs subject to color channels, and then sharing sharp information across channels, we preserve details as well as color fidelity. We prototype two diffractive imaging systems that work in the monochromatic and RGB color domain. Experimental results indicate that the depth-of-field can be significantly extended with fewer artifacts remaining after the deconvolution.","PeriodicalId":413914,"journal":{"name":"2018 IEEE International Conference on Computational Photography (ICCP)","volume":"363 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125813414","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 photography through realistic fog","authors":"Guy Satat, Matthew Tancik, R. Raskar","doi":"10.1109/ICCPHOT.2018.8368463","DOIUrl":"https://doi.org/10.1109/ICCPHOT.2018.8368463","url":null,"abstract":"Imaging through fog has important applications in industries such as self-driving cars, augmented driving, airplanes, helicopters, drones and trains. Here we show that time profiles of light reflected from fog have a distribution (Gamma) that is different from light reflected from objects occluded by fog (Gaussian). This helps to distinguish between background photons reflected from the fog and signal photons reflected from the occluded object. Based on this observation, we recover reflectance and depth of a scene obstructed by dense, dynamic, and heterogeneous fog. For practical use cases, the imaging system is designed in optical reflection mode with minimal footprint and is based on LIDAR hardware. Specifically, we use a single photon avalanche diode (SPAD) camera that time-tags individual detected photons. A probabilistic computational framework is developed to estimate the fog properties from the measurement itself, without prior knowledge. Other solutions are based on radar that suffers from poor resolution (due to the long wavelength), or on time gating that suffers from low signal-to-noise ratio. The suggested technique is experimentally evaluated in a wide range of fog densities created in a fog chamber It demonstrates recovering objects 57cm away from the camera when the visibility is 37cm. In that case it recovers depth with a resolution of 5cm and scene reflectance with an improvement of 4dB in PSNR and 3.4x reconstruction quality in SSIM over time gating techniques.","PeriodicalId":413914,"journal":{"name":"2018 IEEE International Conference on Computational Photography (ICCP)","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121947475","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}
David B. Lindell, Matthew O'Toole, Gordon Wetzstein
{"title":"Towards transient imaging at interactive rates with single-photon detectors","authors":"David B. Lindell, Matthew O'Toole, Gordon Wetzstein","doi":"10.1109/ICCPHOT.2018.8368466","DOIUrl":"https://doi.org/10.1109/ICCPHOT.2018.8368466","url":null,"abstract":"Active imaging at the picosecond timescale reveals transient light transport effects otherwise not accessible by computer vision and image processing algorithms. For example, analyzing the time of flight of short laser pulses emitted into a scene and scattered back to a detector allows for depth imaging, which is crucial for autonomous driving and many other applications. Moreover, analyzing or removing global light transport effects from photographs becomes feasible. While several transient imaging systems have recently been proposed using various imaging technologies, none is capable of acquiring transient images at interactive framerates. In this paper, we present an imaging system that records transient images at up to 25 Hz. We show several transient video clips recorded with this system and demonstrate transient imaging applications, including direct-global light transport separation and enhanced depth imaging.","PeriodicalId":413914,"journal":{"name":"2018 IEEE International Conference on Computational Photography (ICCP)","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124659690","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":"Reconfigurable rainbow PIV for 3D flow measurement","authors":"J. Xiong, Q. Fu, R. Idoughi, W. Heidrich","doi":"10.1109/ICCPHOT.2018.8368475","DOIUrl":"https://doi.org/10.1109/ICCPHOT.2018.8368475","url":null,"abstract":"In recent years, 3D Particle Imaging Velocimetry (PIV) has become more and more attractive due to its ability to fully characterize various fluid flows. However, 3D fluid capture and velocity field reconstruction remain a challenging problem. A recent rainbow PIV system encodes depth into color and successfully recovers 3D particle trajectories, but it also suffers from a limited and fixed volume size, as well as a relatively low light efficiency. In this paper, we propose a reconfigurable rainbow PIV system that extends the volume size to a considerable range. We introduce a parallel double-grating system to improve the light efficiency for scalable rainbow generation. A varifocal encoded diffractive lens is designed to accommodate the size of the rainbow illumination, ranging from 15 mm to 50 mm. We also propose a truncated consensus ADMM algorithm to efficiently reconstruct particle locations. Our algorithm is 5x faster compared to the state-of-the-art. The reconstruction quality is also improved significantly for a series of density levels. Our method is demonstrated by both simulation and experimental results.","PeriodicalId":413914,"journal":{"name":"2018 IEEE International Conference on Computational Photography (ICCP)","volume":"2014 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128944902","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":"Near-light photometric stereo using circularly placed point light sources","authors":"Chao Liu, S. Narasimhan, A. Dubrawski","doi":"10.1109/ICCPHOT.2018.8368465","DOIUrl":"https://doi.org/10.1109/ICCPHOT.2018.8368465","url":null,"abstract":"Most photometric stereo approaches assume distant or directional lighting and orthographic imaging. However, when the source is divergent and is near the object and the camera is projective, the image intensity of a Lambertian object is a non-linear function of both the unknown surface normals and the unknown distances of the source to the surface points. The resulting non-linear optimization is non-convex and highly sensitive to the initial guess. In this paper, we propose a two-stage near-light photometric stereo method using circularly placed point light sources (commonly seen in recent consumer imaging devices like NESTcam, Amazon Cloudcam, etc). We represent the scene using a 3D mesh and directly optimize the vertices of the mesh. This reduces the complexity of the relationship between surface normals and depths in the image formation model. In the first stage, we optimize the vertex positions using the differential images induced by small changes in light source position. This procedure yields a strong initial guess for the second stage that refines the estimations using the raw captured images. We propose an accurate calibration approach to estimate the positions of the sources. Our approach performs better on simulations and on real Lambertian scenes with complex shapes than the state-of-the-art method with near-field lighting.","PeriodicalId":413914,"journal":{"name":"2018 IEEE International Conference on Computational Photography (ICCP)","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126178894","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}
Itzik Malkiel, M. Mrejen, Achiya Nagler, U. Arieli, Lior Wolf, H. Suchowski
{"title":"Deep learning for the design of nano-photonic structures","authors":"Itzik Malkiel, M. Mrejen, Achiya Nagler, U. Arieli, Lior Wolf, H. Suchowski","doi":"10.1109/ICCPHOT.2018.8368462","DOIUrl":"https://doi.org/10.1109/ICCPHOT.2018.8368462","url":null,"abstract":"Our visual perception of our surroundings is ultimately limited by the diffraction-limit, which stipulates that optical information smaller than roughly half the illumination wavelength is not retrievable. Over the past decades, many breakthroughs have led to unprecedented imaging capabilities beyond the diffraction-limit, with applications in biology and nanotechnology. In this context, nano-photonics has had a profound impact on the field of optics by enabling the manipulation of light-matter interaction with subwave-length structures [1, 2, 3]. However, despite the many advances in this field, its impact and penetration in our daily life has been hindered by a convoluted and iterative process, cycling through modeling, nanofabrication and nano-characterization. The fundamental reason is the fact that not only the prediction of the optical response is very time consuming and requires solving Maxwell's equations with dedicated numerical packages [4, 5, 6]. But, more significantly, the inverse problem, i.e. designing a nanostructure with an on-demand optical response, is currently a prohibitive task even with the most advanced numerical tools due to the high non-linearity of the problem [7, 8]. Here, we harness the power of Deep Learning and show its ability to predict the geometry of nanostructures based solely on their far-field response. This approach addresses in a direct way the currently inaccessible inverse problem breaking the ground for on-demand design of optical response with applications such as sensing, imaging and also for Plasmons mediated cancer thermotherapy.","PeriodicalId":413914,"journal":{"name":"2018 IEEE International Conference on Computational Photography (ICCP)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129388329","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}