Fast general multipath correction in time-of-flight imaging

Abstract

Fast general multipath correction in time of flight imaging is described, for example, to obtain accurate depth maps at frame rate from a time of flight camera. In various embodiments accurate depth maps are calculated by looking up corrected depth values stored in a look up table. In various embodiments, the corrected depth values are highly accurate as they take into account three or more possible light ray paths between the camera and a surface in a scene being imaged. In an example, accurate depth maps are computed at a frame rate of a time of flight camera. In an example, accurate depth maps are computed in less than 30 milliseconds for an image having over 200,000 pixels using a standard CPU.

Description

Background technique [0001] Time of flight imaging is one type of depth sensing technology used in many computer vision applications, such as object tracking and recognition, human activity analysis, gesture analysis, and indoor 3D mapping, among others. [0002] A time-of-flight system includes one or more light sources that emit light into a scene, and a light sensor such as a camera. Time-of-flight systems work by calculating the time, measured as a phase shift, it takes for emitted light to reflect from a surface and return to a camera at the system. This gives a measure of the surface's depth from the camera. Time-of-flight systems are generally capable of achieving reasonable accuracy, and among others, they use light in the infrared spectrum in order to operate in low lighting settings. [0003] However, time-of-flight systems face multipath interference (hereinafter simply referred to as "multipath"). Here, emitted light is sent out for each pixel, and because light...

AI Technical Summary

Problems solved by technology

This results in corrupted sensor measurements

These corruptions are not like ordinary noise and can be quite large, resulting in very imprecise depth estimates

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