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Multi-View Photometric Stereo

The goal of the Multi-View Photometric Stereo project is to employ controlled lighting to achieve fast and a highly accurate surface analysis and 3D reconstruction of an object. For the generation of illumination patterns, a large spherical metal frame (diameter 216 cm) is constructed from two moveable geodesic domes. The sphere is equipped with a total of 2202 RGB LEDs.

Using a microcontroller each of these LEDs can be individually regulated and each can emit a mixture of red, green and blue light. Driving all LEDs of the LightSphere requires only 6.2 milliseconds (160 Hz). Therefore, it is possible to display various lighting patterns in a very short time, which enables measuring dynamic objects. Through an easy-to-use software interface different lighting sequences can be created and passed to the hardware.

One option for 3D reconstruction is to employ the so-called photometric stereo approach. By illuminating the object with several light patterns, the normal of a surface point can be estimated. When capturing an image with a camera, a surface normal it is determined for each pixel. With a high-resolution camera, it is thus possible, for example, to generate a 3D reconstruction of a face in which individual pores are recognizable.

Publications

• J. Gan, P. Bergen, T. Thormählen, P. Drescher, R. Hagens:
  "Normal Map Bias Reduction for Many-Lights Multi-View Photometric Stereo"
  24th International Symposium on Vision, Modeling, and Visualization (VMV 2019)
  Rostock, Germany, Sep 30 - Oct 2, 2019
  2019
• J. Gan, A. Wilbert, T. Thormählen, P. Drescher, R. Hagens:
  "Multi-View Photometric Stereo using Surface Deformation"
  The Visual Computer, Volume 34, 2018
  2018
• M. Grochulla, T. Thormählen:
  "Combining Photometric Normals and Multi-View Stereo for 3D Reconstruction"
  12th European Conference on Visual Media Production (CVMP 2015)
  London, UK, 24-25 November 2015
  2015