Alex Chapiro

I am a Senior Researcher at Facebook Reality Labs. I previously worked in the Core Display Incubation team at Apple and Applied Vision Science team at Dolby Laboratories. Before that I was at Disney Research in Zurich, advised by Aljoscha Smolic.

I did my PhD at ETH Zurich, where I was advised by Markus Gross at the Computer Graphics Laboratory. I did my masters at IMPA in the Visgraf lab and my bachelors at the Federal University of Juiz de Fora.

Email  /  CV  /  Biography  /  Thesis  /  Google Scholar  /  LinkedIn


I am interested in image and video processing, computational capture and display, stereo 3D, HDR, applied perception and virtual reality. Most of my research deals with creating and then displaying high quality content on novel displays.


FovVideoVDP: A Visible Difference Predictor for Wide Field-of-View Video
Mantiuk, Denes, Chapiro, Kaplanyan, Rufo, Bachy, Lian, Patney
ACM Transactions on Graphics, Proceedings of the ACM SIGGRAPH Conference and Exhibition (SIGGRAPH 2021)
supplementary material / bibtex / github / project page

We created a new foveated spatiotemporal metric, following the VDP line of work. This metric is fast, easy to use and has been carefully calibrated on several large datasets.

ACM TOG 2019

A Luminance-Aware Model of Judder Perception
Chapiro, Atkins, Daly.
ACM Transactions on Graphics 2019, Presented at the ACM SIGGRAPH Conference and Exhibition (SIGGRAPH 2020)
Link to ACM TOG / supplementary material / bibtex / code / presentation video

We studied the main perceptual components of judder, the perceptual artifact of non-smooth motion. In particular, adaptation luminance is a strong factor on judder that has changed significantly with modern generations of displays.

Errata: In the table of coefficients in Sec. A3, the two-before-last coefficient should be ~0 instead of 1.01. The coefficient is correctly written out in the supplementary material, but not in the manuscript.

ACM TAP 2018

Influence of Screen Size and Field of View on Perceived Brightness
Chapiro, Kunkel, Atkins, Daly.
ACM Transactions on Applied Perception (TAP) , 2018
Link to ACM TAP / supplementary material / bibtex

Author's version available here, link to ACM TAP version above. We studied the influence of screen size and distance on perceived brightness for screens as large as cinema and as small as mobile phones, an issue that affects artistic intent and appearance matching.


Unfolding the 8-bit Era
Zund, Berard, Chapiro, Schmid, Ryffel, Bermano, Gross, Sumner.
European Conference on Visual Media Production (CVMP) , 2015
project page / bibtex

We created an immersive gaming system out of a legacy console.

This work received wide media attention and was presented at the Ludicious game festival in Zurich.


Art-Directable/Continuous Dynamic Range Video
Chapiro, Aydin, Stefanoski, Croci, Smolic, Gross.
Computers and Graphics (CG&A) , 2015
project page / bibtex

We defined the production and distribution challenges facing the content creation industry in the current HDR landscape and proposed Continuous Dynamic Range video as a solution.


Video Content and Structure Description Based on Keyframes, Clusters and Storyboards
Junyent, Beltran, Farre, Pont-Tuset, Chapiro, Smolic.
IEEE International Workshop on Multimedia Signal Processing (MMSP) , 2015
video / bibtex

We developed a pipeline to segment and analyze video. Our technique could be applied for smarter editing.


Stereo from Shading
Chapiro, O'Sullivan, Jarosz, Gross, Smolic.
Eurographics Symposium on Rendering (EGSR) , 2015
project page / bibtex / supplementary

We use non-photorealistic shading as an alternative 3D cue, augmenting the feeling of depth in stereoscopic images.


Perceptual Evaluation of Cardboarding in 3D Content Visualization
Chapiro, O'Sullivan, Jarosz, Gross, Smolic.
ACM Symposium on Applied Perception (SAP), 2014
project page / bibtex

We conducted perceptual experiments to quantify cardboarding - an artifact that occurs when not enough depth is given to a stereoscopic 3D image region.


Optimizing Stereo-to-Multiview Conversion for Autostereoscopic Displays
Chapiro, Heinzle, Aydin, Poulakos, Zwicker, Smolic, Gross.
Eurographics, 2014
project page / bibtex

We measured perceptual aspects of autostereo content and created a depth re-mapping algorithm that tries to optimize content so that the most important regions have a fuller sense of depth while staying within the limits of the technology.


Towards Mobile HDR Video
Castro, Chapiro, Cicconet, Velho.
extended abstract in Eurographics, 2011

We created a capture and processing pipeline to generate HDR video on a mobile phone by taking sequential multiple exposures.


Detection of High Frequency Regions in Multiresolution
Mota, Perez, Castro, Chapiro, Vieira.
International Conference on Image Processing (ICIP), 2009

We improved our edge detector by using eigenvalues.


High Frequency Assessment from Multiresolution Analysis
Castro, Perez, Mota, Chapiro, Vieira, Freire.
International Conference on Computational Science (ICCS), 2009

We detected high frequencies using an orientation tensor and multiresolution.



The Influence of Visual Salience on Video Consumption Behavior A Survival Analysis Approach
Huber, Scheibehenne, Chapiro, Frey, Sumner.
ACM Web Science, 2015
long paper version

We found that visual saliency can be used as a predictor for video watching behavior in online platforms.


Filter Based Deghosting for Exposure Fusion Video
Chapiro, Cicconet, Velho.

We used an aditional per-pixel parameter to avoid ghosting from motion when generating exposure-fusion videos on a mobile phone. (Student research competition semi-finalist)


Towards Mobile HDR Video
Castro, Chapiro, Cicconet, Velho.
International Conference on Computational Photography (ICCP), 2011

We created a capture and processing pipeline to generate HDR video on a mobile phone by taking sequential multiple exposures.

Additional publications available upon request.

Website template taken from here