Search Results for author: Ren Ng

Found 21 papers, 13 papers with code

Gravitationally Lensed Black Hole Emission Tomography

no code implementations CVPR 2022 Aviad Levis, Pratul P. Srinivasan, Andrew A. Chael, Ren Ng, Katherine L. Bouman

In this work, we propose BH-NeRF, a novel tomography approach that leverages gravitational lensing to recover the continuous 3D emission field near a black hole.

3D Reconstruction

PlenOctrees for Real-time Rendering of Neural Radiance Fields

5 code implementations ICCV 2021 Alex Yu, RuiLong Li, Matthew Tancik, Hao Li, Ren Ng, Angjoo Kanazawa

We introduce a method to render Neural Radiance Fields (NeRFs) in real time using PlenOctrees, an octree-based 3D representation which supports view-dependent effects.

Neural Rendering Novel View Synthesis

R-SLAM: Optimizing Eye Tracking From Rolling Shutter Video of the Retina

no code implementations ICCV 2021 Jay Shenoy, James Fong, Jeffrey Tan, Austin Roorda, Ren Ng

We present a method for optimization-based recovery of eye motion from rolling shutter video of the retina.

Learned Initializations for Optimizing Coordinate-Based Neural Representations

3 code implementations CVPR 2021 Matthew Tancik, Ben Mildenhall, Terrance Wang, Divi Schmidt, Pratul P. Srinivasan, Jonathan T. Barron, Ren Ng

Coordinate-based neural representations have shown significant promise as an alternative to discrete, array-based representations for complex low dimensional signals.

Meta-Learning

Fourier Features Let Networks Learn High Frequency Functions in Low Dimensional Domains

13 code implementations NeurIPS 2020 Matthew Tancik, Pratul P. Srinivasan, Ben Mildenhall, Sara Fridovich-Keil, Nithin Raghavan, Utkarsh Singhal, Ravi Ramamoorthi, Jonathan T. Barron, Ren Ng

We show that passing input points through a simple Fourier feature mapping enables a multilayer perceptron (MLP) to learn high-frequency functions in low-dimensional problem domains.

Portrait Shadow Manipulation

1 code implementation18 May 2020 Xuaner Cecilia Zhang, Jonathan T. Barron, Yun-Ta Tsai, Rohit Pandey, Xiuming Zhang, Ren Ng, David E. Jacobs

We propose a way to explicitly encode facial symmetry and show that our dataset and training procedure enable the model to generalize to images taken in the wild.

NeRF: Representing Scenes as Neural Radiance Fields for View Synthesis

36 code implementations ECCV 2020 Ben Mildenhall, Pratul P. Srinivasan, Matthew Tancik, Jonathan T. Barron, Ravi Ramamoorthi, Ren Ng

Our algorithm represents a scene using a fully-connected (non-convolutional) deep network, whose input is a single continuous 5D coordinate (spatial location $(x, y, z)$ and viewing direction $(\theta, \phi)$) and whose output is the volume density and view-dependent emitted radiance at that spatial location.

Generalizable Novel View Synthesis Low-Dose X-Ray Ct Reconstruction +2

Video from Stills: Lensless Imaging with Rolling Shutter

1 code implementation30 May 2019 Nick Antipa, Patrick Oare, Emrah Bostan, Ren Ng, Laura Waller

Here, we propose using multiplexing optics to spatially compress the scene, enabling information about the whole scene to be sampled from a row of sensor pixels, which can be read off quickly via a rolling shutter CMOS sensor.

Synthetic Defocus and Look-Ahead Autofocus for Casual Videography

no code implementations15 May 2019 Xuaner Zhang, Kevin Matzen, Vivien Nguyen, Dillon Yao, You Zhang, Ren Ng

We present a system that synthetically renders refocusable video from a deep DOF video shot with a smartphone, and analyzes future video frames to deliver context-aware autofocus for the current frame.

BIG-bench Machine Learning Saliency Detection

Zoom To Learn, Learn To Zoom

1 code implementation13 May 2019 Xuaner Cecilia Zhang, Qifeng Chen, Ren Ng, Vladlen Koltun

We show how to obtain the ground-truth data with optically zoomed images and contribute a dataset, SR-RAW, for real-world computational zoom.

Super-Resolution

Local Light Field Fusion: Practical View Synthesis with Prescriptive Sampling Guidelines

1 code implementation2 May 2019 Ben Mildenhall, Pratul P. Srinivasan, Rodrigo Ortiz-Cayon, Nima Khademi Kalantari, Ravi Ramamoorthi, Ren Ng, Abhishek Kar

We present a practical and robust deep learning solution for capturing and rendering novel views of complex real world scenes for virtual exploration.

Novel View Synthesis

Pushing the Boundaries of View Extrapolation with Multiplane Images

1 code implementation CVPR 2019 Pratul P. Srinivasan, Richard Tucker, Jonathan T. Barron, Ravi Ramamoorthi, Ren Ng, Noah Snavely

We present a theoretical analysis showing how the range of views that can be rendered from an MPI increases linearly with the MPI disparity sampling frequency, as well as a novel MPI prediction procedure that theoretically enables view extrapolations of up to $4\times$ the lateral viewpoint movement allowed by prior work.

StegaStamp: Invisible Hyperlinks in Physical Photographs

3 code implementations CVPR 2020 Matthew Tancik, Ben Mildenhall, Ren Ng

Printed and digitally displayed photos have the ability to hide imperceptible digital data that can be accessed through internet-connected imaging systems.

Steganographics

Single Image Reflection Separation with Perceptual Losses

3 code implementations CVPR 2018 Xuaner Zhang, Ren Ng, Qifeng Chen

Our loss function includes two perceptual losses: a feature loss from a visual perception network, and an adversarial loss that encodes characteristics of images in the transmission layers.

Image Enhancement Reflection Removal +1

Aperture Supervision for Monocular Depth Estimation

no code implementations CVPR 2018 Pratul P. Srinivasan, Rahul Garg, Neal Wadhwa, Ren Ng, Jonathan T. Barron

We present a novel method to train machine learning algorithms to estimate scene depths from a single image, by using the information provided by a camera's aperture as supervision.

Monocular Depth Estimation

DiffuserCam: Lensless Single-exposure 3D Imaging

no code implementations5 Oct 2017 Nick Antipa, Grace Kuo, Reinhard Heckel, Ben Mildenhall, Emrah Bostan, Ren Ng, Laura Waller

We demonstrate a compact and easy-to-build computational camera for single-shot 3D imaging.

Learning to Synthesize a 4D RGBD Light Field from a Single Image

1 code implementation ICCV 2017 Pratul P. Srinivasan, Tongzhou Wang, Ashwin Sreelal, Ravi Ramamoorthi, Ren Ng

We present a machine learning algorithm that takes as input a 2D RGB image and synthesizes a 4D RGBD light field (color and depth of the scene in each ray direction).

Depth Estimation

Light Field Blind Motion Deblurring

no code implementations CVPR 2017 Pratul P. Srinivasan, Ren Ng, Ravi Ramamoorthi

We study the problem of deblurring light fields of general 3D scenes captured under 3D camera motion and present both theoretical and practical contributions.

Deblurring

Oriented Light-Field Windows for Scene Flow

no code implementations ICCV 2015 Pratul P. Srinivasan, Michael W. Tao, Ren Ng, Ravi Ramamoorthi

2D spatial image windows are used for comparing pixel values in computer vision applications such as correspondence for optical flow and 3D reconstruction, bilateral filtering, and image segmentation.

3D Reconstruction Image Segmentation +3

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