CS-ToF: High-resolution compressive time-of-flight imaging

Abstract

Three-dimensional imaging using Time-of-flight (ToF) sensors is rapidly gaining widespread adoption in many applications due to their cost effectiveness, simplicity, and compact size. However, the current generation of ToF cameras suffers from low spatial resolution due to physical fabrication limitations. In this paper, we propose CS-ToF, an imaging architecture to achieve high spatial resolution ToF imaging via optical multiplexing and compressive sensing. Our approach is based on the observation that, while depth is non-linearly related to ToF pixel measurements, a phasor representation of captured images results in a linear image formation model. We utilize this property to develop a CS-based technique that is used to recover high resolution 3D images. Based on the proposed architecture, we developed a prototype 1-megapixel compressive ToF camera that achieves as much as 4× improvement in spatial resolution and 3× improvement for natural scenes. We believe that our proposed CS-ToF architecture provides a simple and low-cost solution to improve the spatial resolution of ToF and related sensors.

Compressive Sensing-Based Three-Dimensional Laser Imaging With Dual Illumination

“…The pulsed laser works at low repetition rate, high pulse energy to illuminate the target scene and a 32 × 32 array illuminator with Dammann grating embedded are carried out for depth estimation as well. A series of DMD patterns derived from 2D Hadamard transform are used to modulate the echo pulses for CS measurements [18]. The main parameters of the LIDAR system are given in Table 1.…”

“…Howland et al [16], [17] combined CS theory with a TOF photon counting LIDAR configuration where transverse spatial resolution is obtained without scanning. Via optical multiplexing, Li et al [18] proposed a CS-TOF imaging architecture which achieved significant improvement in spatial resolution for natural scene. Although these frameworks provide simple and low-cost solutions compared with conventional TOF LIDAR, the range resolution of the systems depends on narrow bandwidth of illumination laser pulses and comparative detectors.…”

Raw Data Processing for Practical Time-of-Flight Super-Resolution

“…A third group, to which this work belongs, would be that of methods using a set of depth images or, more generally, raw images. Furthermore, other less standard techniques exist for ToF-SR, e. g., making use of polarization cues [9], or compressive sensing [10,11], but they require profound hardware modifications.…”

Computational Polarization 3D: new solution for monocular 3D imaging approach in natural conditions

“…Shape information is essential in 3D computer vison with numerous applications ranging from unlocking a phone to city modeling [1][2][3] . Various methods, including time of flight (ToF), structured light illumination, binocular stereo imaging, and Laser radar (LIDAR), have been developed [4][5][6][7][8] . However, all those methods are fairly complicated as special illumination or more than one view are always required.…”