Hi, I'm Chris. (View my resume)
I'm a software engineer at Facebook. I'm primarily interested in topics related to distributed systems and infrastructure.
2022.07.15 - Promotion!
Promoted to Staff Software Engineer at Meta
2020.08.17 - New job!
Joined Facebook as a Software Engineer
2017.03.17 - New job!
Joined RADAR as a Software Engineer
2015.05.11 - New job!
Joined Spotify as a Software Engineer
2015.01.06 - Promotion!
Promoted to Software Development Engineer II at A9.com (an Amazon Company)
2014.01.06 - Started work!
Joined A9.com (an Amazon Company) as a Software Development Engineer
2013.12.18 - Graduated
Graduated from Washington University in St. Louis, with a major in Computer Science and Applied Mathematics
In this work, we present a method to uncover shape from webcams "in the wild." We present a variant of photometric stereo which uses the sun as a distant light source, so that lighting direction can be computed from known GPS and timestamps. We propose an iterative, non-linear optimization process that optimizes the error in reproducing all images from an extended time-lapse with an image formation model that accounts for ambient lighting, shadows, changing light color, dense surface normal maps, radiometric calibration, and exposure. Unlike many approaches to uncalibrated outdoor image analysis, this procedure is automatic, and we report quantitative results by comparing extracted surface normals to Google Earth 3D models. We evaluate this procedure on data from a varied set of scenes and emphasize the advantages of including imagery from many months.