Ioannis Gkioulekas

Ioannis Gkioulekas

I am an associate professor in the Robotics Institute at Carnegie Mellon University. I received my PhD and MS degrees from the School of Engineering and Applied Sciences at Harvard University, and a diploma from the School of Electrical and Computer Engineering at the National Technical University of Athens.

Check out my research, publications, and teaching, some writing and code resources, and my group website.

Research

I work broadly in computer graphics and computer vision, but I focus on computational imaging: this is the joint design of optics, electronics, and computation to create imaging systems with unprecedented capabilities. Some examples include: imaging systems that can see around corners or through skin; passive 3D sensing systems with extreme resolution; ultrafast programmable lenses; imaging systems that adapt to their environments. Technical keywords that often show up in my research include: non-line-of-sight imaging, single-photon imaging, LiDAR, SONAR, interferometry, speckle, acousto-optics, physics-based rendering, differentiable rendering, Monte Carlo simulation, probabilistic modeling.

Publications

fast_dipole_sums

3D reconstruction with fast dipole sums
Hanyu Chen, Bailey Miller, Ioannis Gkioulekas
ACM Transactions on Graphics (SIGGRAPH Asia), 2024

differential_walk_on_spheres

Differential walk on spheres
Bailey Miller, Rohan Sawhney, Keenan Crane, Ioannis Gkioulekas
ACM Transactions on Graphics (SIGGRAPH Asia), 2024

walk_on_stars_robin

Walkin' Robin: Walk on stars with Robin boundary conditions
Bailey Miller*, Rohan Sawhney*, Keenan Crane, Ioannis Gkioulekas
ACM Transactions on Graphics (SIGGRAPH), 2024(best paper award)

aperture_aware_lens_design

Aperture-aware lens design
Arjun Teh, Ioannis Gkioulekas, Matthew O'Toole
SIGGRAPH, 2024

path_sampling_differentiable_rendering

Path sampling methods for differentiable rendering
Tanli Su, Ioannis Gkioulekas
Eurographics Symposium on Rendering (EGSR), 2024

volumetric_opaque_solids

Objects as volumes: A stochastic geometry view of opaque solids
Bailey Miller, Hanyu Chen, Alice Lai, Ioannis Gkioulekas
IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR), 2024(best student paper award)

loops

Trilateration using unlabeled path or loop lengths
Ioannis Gkioulekas, Steven J. Gortler, Louis Theran, Todd Zickler
Discrete & Computational Geometry, 2023

dopplertof

Doppler time-of-flight rendering
Juhyeon Kim, Wojciech Jarosz, Ioannis Gkioulekas, Adithya Pediredla
ACM Transactions on Graphics (SIGGRAPH Asia), 2023

optimized_virtual_optical_waveguides

Optimized virtual optical waveguides enhance light throughput in scattering media
Adithya Pediredla*, Matteo Giuseppe Scopelliti*, Srinivasa G. Narasimhan, Maysamreza Chamanzar, Ioannis Gkioulekas
Nature Communications, 2023

speckle_temporal

Efficient Monte Carlo simulation of spatiotemporal speckles and their correlations
Chen Bar, Ioannis Gkioulekas, Anat Levin
Optica, 2023

wost

Walk on stars: A grid-free Monte Carlo method for PDEs with Neumann boundary conditions
Rohan Sawhney*, Bailey Miller*, Ioannis Gkioulekas, Keenan Crane
ACM Transactions on Graphics (SIGGRAPH), 2023

bvc

Boundary value caching for walk on spheres
Bailey Miller*, Rohan Sawhney*, Keenan Crane, Ioannis Gkioulekas
ACM Transactions on Graphics (SIGGRAPH), 2023

ultrafast_steering

Megahertz light steering without moving parts
Adithya Pediredla, Srinivasa G. Narasimhan, Maysamreza Chamanzar, Ioannis Gkioulekas
IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR), 2023

sunlight_interferometry

Passive micron-scale time-of-flight with sunlight interferometry
Alankar Kotwal, Anat Levin, Ioannis Gkioulekas
IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR), 2023(highlight)

swept_angle_swi

Swept-angle synthetic wavelength interferometry
Alankar Kotwal, Anat Levin, Ioannis Gkioulekas
IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR), 2023(highlight)

neural_kaleidoscopic_space_sculpting

Neural kaleidoscopic space sculpting
Byeongjoo Ahn, Michael De Zeeuw, Ioannis Gkioulekas, Aswin C. Sankaranarayanan
IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR), 2023

neusis

Neural implicit surface reconstruction using imaging sonar
Mohamad Qadri, Michael Kaess, Ioannis Gkioulekas
IEEE International Conference on Robotics and Automation (ICRA), 2023

adjoint_nonlinear_tracing

Adjoint nonlinear ray tracing
Arjun Teh, Matthew O'Toole, Ioannis Gkioulekas
ACM Transactions on Graphics (SIGGRAPH), 2022

wavefront_shaping

Fluorescent wavefront shaping using incoherent iterative phase conjugation
Dror Aizik, Ioannis Gkioulekas, Anat Levin
Optica, 2022

meshsdf

Physics-based inverse rendering using combined implicit and explicit geometries
Guangyan Cai, Kai Yan, Zhao Dong, Ioannis Gkioulekas, Shuang Zhao
Computer Graphics Forum (EGSR), 2022

adaptive_gating

Adaptive gating for single-photon 3D imaging
Po Ryan, Adithya Pediredla, Ioannis Gkioulekas
IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR), 2022(oral)

overwhelming

Reply to: The overwhelming role of ballistic photons in ultrasonically guided light through tissue
Maysamreza Chamanzar, Matteo Giuseppe Scopelliti, Adithya Pediredla, Hengji Huang, Srinivasa G. Narasimhan, Ioannis Gkioulekas, Mohammad-Reza Alam, Michel M. Maharbiz
Nature Communications, 2022

kaleidoscopic_structured_light

Kaleidoscopic structured light
Byeongjoo Ahn, Ioannis Gkioulekas, Aswin C. Sankaranarayanan
ACM Transactions on Graphics (SIGGRAPH Asia), 2021

dual_pixels

Defocus map estimation and deblurring From a single dual-pixel image
Shumian Xin, Neal Wadhwa, Tianfan Xue, Jonathan T. Barron, Pratul Srinivasan, Jiawen Chen, Ioannis Gkioulekas, Rahul Garg
IEEE/CVF International Conference on Computer Vision (ICCV), 2021(oral)

correlations

Imaging with local speckle intensity correlations: Theory and practice
Marina Alterman, Chen Bar, Ioannis Gkioulekas, Anat Levin
ACM Transactions on Graphics, 2021

speckle_single

Single scattering modeling of speckle correlation
Chen Bar, Marina Alterman, Ioannis Gkioulekas, Anat Levin
IEEE International Conference on Computational Photography (ICCP), 2021

tradeoff

Overcoming the tradeoff between confinement and focal distance using virtual ultrasonic optical waveguides
Matteo Giuseppe Scopelliti, Hengji Huang, Adithya Pediredla, Srinivasa G. Narasimhan, Ioannis Gkioulekas, Maysamreza Chamanzar
Optics Express, 2020

rrte

Path tracing estimators for refractive radiative transfer
Adithya Pediredla, Yasin Karimi Chalmiani, Matteo Giuseppe Scopelliti, Maysamreza Chamanzar, Srinivasa G. Narasimhan, Ioannis Gkioulekas
ACM Transactions on Graphics (SIGGRAPH Asia), 2020

speckle_near

Rendering near-field speckle statistics in scattering media
Chen Bar, Ioannis Gkioulekas, Anat Levin
ACM Transactions on Graphics (SIGGRAPH Asia), 2020

fermat_sonar

A theory of Fermat paths for 3D imaging sonar reconstruction
Eric Westman, Ioannis Gkioulekas, Michael Kaess
IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2020

lmc

Langevin Monte Carlo rendering with gradient-based adaptation
Fujun Luan, Shuang Zhao, Kavita Bala, Ioannis Gkioulekas
ACM Transactions on Graphics (SIGGRAPH), 2020

psdr

Path-space differentiable rendering
Cheng Zhang, Bailey Miller, Kai Yan, Ioannis Gkioulekas, Shuang Zhao
ACM Transactions on Graphics (SIGGRAPH), 2020

coded_mutual_intensity

Interferometric transmission probing with coded mutual intensity
Alankar Kotwal, Anat Levin, Ioannis Gkioulekas
ACM Transactions on Graphics (SIGGRAPH), 2020

sharpness

Effect of geometric sharpness on translucent material perception
Bei Xiao, Shuang Zhao, Ioannis Gkioulekas, Wenyan Bi, Kavita Bala
Journal of Vision (JOV), 2020

albedo_sonar

A volumetric albedo framework for 3D imaging sonar reconstruction
Eric Westman, Ioannis Gkioulekas, Michael Kaess
IEEE International Conference on Robotics and Automation (ICRA), 2020

multibounce_reflectometry

Towards reflectometry from interreflections
Kfir Shem-Tov*, Sai Praveen Bangaru*, Anat Levin, Ioannis Gkioulekas
IEEE International Conference on Computational Photography (ICCP), 2020

inverse_transport_networks

Towards learning-based inverse subsurface scattering
Chengqian Che, Fujun Luan, Shuang Zhao, Kavita Bala, Ioannis Gkioulekas
IEEE International Conference on Computational Photography (ICCP), 2020

conv_nlos

Convolutional approximations to the general non-line-of-sight imaging operator
Byeongjoo Ahn, Akshat Dave, Ashok Veeraraghavan, Ioannis Gkioulekas, Aswin C. Sankaranarayanan
IEEE/CVF International Conference on Computer Vision (ICCV), 2019(oral)

dtrt

A differential theory of radiative transfer
Cheng Zhang, Lifan Wu, Changxi Zheng, Ioannis Gkioulekas, Ravi Ramamoorthi, Shuang Zhao
ACM Transactions on Graphics (SIGGRAPH Asia), 2019

ellipsoidal_connections

Ellipsoidal path connections for time-gated rendering
Adithya Pediredla, Ashok Veeraraghavan, Ioannis Gkioulekas
ACM Transactions on Graphics (SIGGRAPH), 2019

speckle

A Monte Carlo framework for rendering speckle statistics in scattering media
Chen Bar, Marina Alterman, Ioannis Gkioulekas, Anat Levin
ACM Transactions on Graphics (SIGGRAPH), 2019

fermat_paths

A theory of Fermat paths for non-line-of-sight shape reconstruction
Shumian Xin, Sotiris Nousias, Kiriakos N. Kutulakos, Aswin C. Sankaranarayanan, Srinivasa G. Narasimhan, Ioannis Gkioulekas
IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR), 2019(best paper award)

nlos_surf_opt

Beyond volumetric albedo—A surface optimization framework for non-line-of-sight imaging
Chia-Yin Tsai, Aswin C. Sankaranarayanan, Ioannis Gkioulekas
IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR), 2019

inverse_transient

An evaluation of computational imaging techniques for heterogeneous inverse scattering
Ioannis Gkioulekas, Anat Levin, Todd Zickler
European Conference on Computer Vision (ECCV), 2016(highlight)

transient

Micron-scale light transport decomposition using interferometry
Ioannis Gkioulekas, Anat Levin, Frédo Durand, Todd Zickler
ACM Transactions on Graphics (SIGGRAPH), 2015

translucentedges

On the appearance of translucent edges
Ioannis Gkioulekas, Bruce Walter, Edward H. Adelson, Kavita Bala, Todd Zickler
IEEE Conference on Computer Vision and Pattern Recognition (CVPR), 2015

perception

Looking against the light: How perception of translucency depends on lighting direction
Bei Xiao, Bruce Walter, Ioannis Gkioulekas, Todd Zickler, Edward H. Adelson, Kavita Bala
Journal of Vision (JOV), 2014

acquisition

Inverse volume rendering with material dictionaries
Ioannis Gkioulekas, Shuang Zhao, Kavita Bala, Todd Zickler, Anat Levin
ACM Transactions on Graphics (SIGGRAPH Asia), 2013

translucency

Understanding the role of phase function in translucent appearance
Ioannis Gkioulekas, Bei Xiao, Shuang Zhao, Edward H. Adelson, Todd Zickler, Kavita Bala
ACM Transactions on Graphics, 2013

vss

Effects of shape and color on the perception of translucency
Bei Xiao, Ioannis Gkioulekas, Asher Dunn, Shuang Zhao, Todd Zickler, Edward H. Adelson, Kavita Bala
Vision Science Society Annual Meeting (VSS), 2012

microvision

Toward wide-angle microvision sensors
Sanjeev J. Koppal, Ioannis Gkioulekas, Travis Young, Hyunsung Park, Kenneth B. Crozier, Geoffrey L. Barrows, Todd Zickler
IEEE Transactions on Pattern Analysis and Machine Intelligence (PAMI), 2013

sparseldr

Dimensionality reduction using the sparse linear model
Ioannis Gkioulekas, Todd Zickler
Advances in Neural Information Processing Systems (NIPS), 2011

microsensor

Wide-angle micro sensors for vision on a tight budget
Sanjeev J. Koppal, Ioannis Gkioulekas, Todd Zickler, Geoffrey L. Barrows
IEEE Conference on Computer Vision and Pattern Recognition (CVPR), 2011(oral)

surprise

Spatial Bayesian surprise for image saliency and quality assessment
Ioannis Gkioulekas, Giorgos Evangelopoulos, Petros Maragos
IEEE International Conference on Image Processing (ICIP), 2010

Teaching

15463

15-463, 15-663, 15-862 Computational photography
Instructor, CMU, 2017 - present

15468

15-468, 15-668, 15-868 Physics-based rendering
Instructor, CMU, 2021 - present

Interferometry SIGGRAPH 2023

Computational interferometric imaging
Organizer, SIGGRAPH 2023 course

PBR CVPR 2023

Physics-based rendering and its applications in computational photography and imaging
Organizer, CVPR 2023 tutorial

PBDR CVPR 2021

Physics-based differentiable rendering
Organizer, CVPR 2021 tutorial

16385

16-385 Computer vision
Instructor, CMU, 2018 - 2020

sparseldr

CS283 Computer vision
Teaching fellow, Harvard, 2010, 2012 - 2015

Writing

Take a read through my technical writing suggestions, which draw a lot of inspiration from Wojciech Jarosz's common mistakes in technical writing.

Code

Visit the CMU Computational Imaging GitHub account for code for projects at CMU. You can find code for some older projects at my personal GitHub account. I use these coding and style conventions in all of my projects.