Structured light 3D in the presence of Global Illumination

The goal of this work is to build an end-to-end system for structured light 3D scanning under a broad range of global illumination effects, such as inter-reflections, diffusion and sub-surface scattering. We have designed structured light patterns that are resilient to individual global illumination effects using simple logical operations and tools from combinatorial mathematics. Scenes exhibiting multiple phenomena are handled by combining results from a small ensemble of such patterns. Our methods can be readily incorporated into existing scanning systems without a significant overhead in terms of capture time or hardware.
Image Scene
Image Depth Map (Our Technique)
Image 3D Visualization
Previous Technique
Image Conventional Gray Codes
Image Modulated Phase Shifting
The scene shown above has significant global illumination in the form of interreflections and sub-surface scattering. Conventional Gray codes and phase-shifting result in errors at points receiving inter-reflections. Modulated phase-shifting produces errors on translucent fruits. In contrast, the depth map computed using our techniques is nearly error free. Please see the compilation of results below for more examples.

Publications


"Structured Light 3D Scanning in the Presence of Global Illumination"
Mohit Gupta, Amit Agrawal, Ashok Veeraraghavan, Srinivasa G. Narasimhan,
IEEE Computer Vision and Pattern Recognition (CVPR),
June, 2011.

"A Practical Approach to 3D Scanning in the Presence of Interre.ections, Subsurface Scattering and Defocus"
Mohit Gupta, Amit Agrawal, Ashok Veeraraghavan and Srinivasa G. Narasimhan
International Journal of Computer Vision (IJCV),
2012.

Image IJCV 2012
Image CVPR 2011
Image Presentation with Results
Image Poster

Gallery of Results


Illustration of our techniques on simple shapes:


Scenes with multiple global illumination effects:
Image Image Image Image


Translucent objects (sub-surface scattering and diffusion) and defocus:
Image Image Image Image


Metal lamp with strong high-frequency interreflections:
Illustration of error correction and detection
Image

Structured Light Patterns and MATLAB Code

Image Patterns
Image MATLAB Code