Exploiting time-multiplexing structured light with picoprojectors

Giuffrida, Mario Valerio; Farinella, Giovanni Maria; Battiato, Sebastiano; Guarnera, Mirko

Abstract

When a picture is shot all the information about the distance between the object and the camera gets lost. Depth estimation from a single image is a notable issue in computer vision. In this work we present a hardware and software framework to accomplish the task of 3D measurement through structured light. This technique allows to estimate the depth of the objects, by projecting specific light patterns on the measuring scene. The potentialities of the structured light are well-known in both scientific and industrial contexts. Our framework uses a picoprojector module provided by STMicroelectronics, driven by the designed software projecting time- multiplexing Gray code light patterns. The Gray code is an alternative method to represent binary numbers, ensuring that the hamming distance between two consecutive numbers is always one. Because of this property, this binary coding gives better results for depth estimation task. Many patterns are projected at different time instants, obtaining a dense coding for each pixel. This information is then used to compute the depth for each point in the image. In order to achieve better results, we integrate the depth estimation with the inverted Gray code patterns as well, to compensate projector-camera synchronization problems as well as noise in the scene. Even though our framework is designed for laser picoprojectors, it can be used with conventional image projectors and we present the results for this case too.

• Presentation Conference Type: Conference Paper (Published)
• Conference Name: IS&T/SPIE Electronic Imaging 2015
• Start Date: Feb 8, 2015
• End Date: Feb 12, 2015
• Online Publication Date: Mar 17, 2015
• Publication Date: 2015
• Deposit Date: Sep 13, 2023
• Series Title: Three-Dimensional Image Processing, Measurement (3DIPM), and Applications
• Series Number: 9393
• Book Title: Three-Dimensional Image Processing, Measurement (3DIPM), and Applications 2015: Proceedings
• ISBN: 9781628414837
• DOI: https://doi.org/10.1117/12.2083031
• Keywords: Structured light, Gray code patterns, Time-multiplexing, Picoprojector, Cameras, Projection systems, Binary data, Pico projectors, Distortion, Software frameworks, Imaging systems, Calibration, Mirrors
• Related Public URLs: https://spie.org/conferences-and-exhibitions/past-conferences-and-exhibitions/electronic-imaging-2015?SSO=1