Computational Discovery of Hidden Cues in Photographs

Images of everyday scenes often contain hidden information that can be extracted to localize objects outside the view of the camera and to see around corners. For example, we show that it is possible to look at shadows cast by an object on a table, such as a teapot, and reconstruct an image of the s...

Full description

Bibliographic Details
Main Author: Swedish, Tristan
Other Authors: Raskar, Ramesh
Format: Thesis
Published: Massachusetts Institute of Technology 2023
Online Access:https://hdl.handle.net/1721.1/151975
_version_ 1826198013854351360
author Swedish, Tristan
author2 Raskar, Ramesh
author_facet Raskar, Ramesh
Swedish, Tristan
author_sort Swedish, Tristan
collection MIT
description Images of everyday scenes often contain hidden information that can be extracted to localize objects outside the view of the camera and to see around corners. For example, we show that it is possible to look at shadows cast by an object on a table, such as a teapot, and reconstruct an image of the surrounding room. We describe how to identify and make use of these hidden cues such as shadows, reflections, and other subtle changes in an image caused by the interaction of light with objects in a scene that are not in the direct-line-of-sight. We use the term computational discovery to describe techniques that can be used to uncover these cues and reveal hidden information. Despite incredible advances in computer vision in recent years, cameras are limited to a single viewpoint of a scene, requiring invasive multi-camera setups or active imaging modalities to solve many perception tasks today. Prior work has identified hidden cues that are present in photographs of certain environments, but these methods often require human insight to identify cues, and extensive calibration to make use of them. In order to address the limitations found in prior work, we propose an end-to-end machine learning framework to identify hidden cues. More generally, we show that object localization is approximately equal to localizing a point light source, and describe how this insight can be used to identify situations when object localization is possible. Furthermore, we show that physically-based "inverse rendering" can be used to estimate how light travels within a scene, turning objects, like coffee cups or picture frames, into "object cameras". Physical models are quite fragile to small errors in estimated scene parameters. As such, we suggest reconstruction methods that make use of the uncertainty in scene parameters to improve robustness. The thesis suggests a number of other interesting ways hidden cues may be used in combination with imaging systems. This work could inspire future cameras that incorporate the environment itself as part of the imaging system, blurring the line between observer and subject.
first_indexed 2024-09-23T10:57:31Z
format Thesis
id mit-1721.1/151975
institution Massachusetts Institute of Technology
last_indexed 2024-09-23T10:57:31Z
publishDate 2023
publisher Massachusetts Institute of Technology
record_format dspace
spelling mit-1721.1/1519752023-09-01T03:39:06Z Computational Discovery of Hidden Cues in Photographs Swedish, Tristan Raskar, Ramesh Raskar, Ramesh Program in Media Arts and Sciences (Massachusetts Institute of Technology) Images of everyday scenes often contain hidden information that can be extracted to localize objects outside the view of the camera and to see around corners. For example, we show that it is possible to look at shadows cast by an object on a table, such as a teapot, and reconstruct an image of the surrounding room. We describe how to identify and make use of these hidden cues such as shadows, reflections, and other subtle changes in an image caused by the interaction of light with objects in a scene that are not in the direct-line-of-sight. We use the term computational discovery to describe techniques that can be used to uncover these cues and reveal hidden information. Despite incredible advances in computer vision in recent years, cameras are limited to a single viewpoint of a scene, requiring invasive multi-camera setups or active imaging modalities to solve many perception tasks today. Prior work has identified hidden cues that are present in photographs of certain environments, but these methods often require human insight to identify cues, and extensive calibration to make use of them. In order to address the limitations found in prior work, we propose an end-to-end machine learning framework to identify hidden cues. More generally, we show that object localization is approximately equal to localizing a point light source, and describe how this insight can be used to identify situations when object localization is possible. Furthermore, we show that physically-based "inverse rendering" can be used to estimate how light travels within a scene, turning objects, like coffee cups or picture frames, into "object cameras". Physical models are quite fragile to small errors in estimated scene parameters. As such, we suggest reconstruction methods that make use of the uncertainty in scene parameters to improve robustness. The thesis suggests a number of other interesting ways hidden cues may be used in combination with imaging systems. This work could inspire future cameras that incorporate the environment itself as part of the imaging system, blurring the line between observer and subject. Ph.D. 2023-08-30T15:55:23Z 2023-08-30T15:55:23Z 2022-09 2023-08-16T20:45:52.440Z Thesis https://hdl.handle.net/1721.1/151975 0000-0002-5453-6121 In Copyright - Educational Use Permitted Copyright MIT http://rightsstatements.org/page/InC-EDU/1.0/ application/pdf Massachusetts Institute of Technology
spellingShingle Swedish, Tristan
Computational Discovery of Hidden Cues in Photographs
title Computational Discovery of Hidden Cues in Photographs
title_full Computational Discovery of Hidden Cues in Photographs
title_fullStr Computational Discovery of Hidden Cues in Photographs
title_full_unstemmed Computational Discovery of Hidden Cues in Photographs
title_short Computational Discovery of Hidden Cues in Photographs
title_sort computational discovery of hidden cues in photographs
url https://hdl.handle.net/1721.1/151975
work_keys_str_mv AT swedishtristan computationaldiscoveryofhiddencuesinphotographs