Science and Technology - For Students

Stereo Workstation

MSSL, UCL is developing a stereo workstation application within the ProVisG project since Dec. 2008 and this subtask runs till Aug. 2011.

ProVisG T3.7 description states that this aims to:
“Synchronise other stereo workstation efforts so they are harmonised with joint development work with JPL, provide information on mutual efforts and on student project work”

We interpret this as:

  • Collecting all possible stereo algorithms and integrating them into JPL’s stereo rendering engine
  • Obtain feedback or help from JPL if and when required and report implementation issues to JPL
  • Providing demos to students at workshops as a part of public outreach

Stereo Workstation

The stereo workstation as currently implemented at MSSL appears in the adjacent picture. This is a passive stereo display and polarising glasses are required to view the combined image of the two LCD monitors via a half silvered (i.e. semi transparent) mirror. For the top monitor image it’s polarisation is modified upon reflection in the half silvered mirror to align with the polarisation direction of the above the user’s right eye. The lower monitor image passes straight through the mirror aligned with the polarisation direction of the lens above the left eye.

The JADIS stereo rendering engine written by JPL has the following capabilities:

  • It is written in Java using standard mechanisms for cross-platform compatibility.
  • Provides support for any Swing component that uses the standard Java Graphics/Graphics2D rendering mechanism.
  • Uses OpenGL to perform all rendering and to control a stereo-capable graphics card (if available)
  • Stereo modes supported:
    • Anaglyph (with the ability to “simulate” colour stereo)
    • OpenGL Quad-Buffer Stereo using shutter glasses
  • Requirements for Hardware Stereo mode
    • CRT or Front Projection Display (maybe some plasmas but not LCD) capable of high refresh rate (100-120Hz)
    • Supports graphics cards that have a stereo port and support OpenGL quad-buffer stereo.  E.g.: the NVIDIA Quadro4 series.
    • Library: JOGL, JAI, Jade display (optional library of java)
  • Current supported platforms include Intel Linux, Microsoft Windows, Sun/Solaris and Mac OSX.
Processing Pipleline using the "GOTCHA" stereo matching algorithm
Processing Pipeline using the "GOTCHA" stereo matching algorithm

MSSL plans to supplement the JADIS software’s capabilities by adding several additional stereo-matching algorithms. As an example the adjacent figure shows the processing pipeline for Mars rover stereo images using the “GOTCHA” stereo matching algorithm.


Triangulation result from a NavCam stereo

MSSL plans to supplement the JADIS software’s capabilities by adding several additional stereo-matching algorithms. As an example the adjacent figure shows the processing pipeline for Mars rover stereo images using the “GOTCHA” stereo matching algorithm.

The output product is a 3D model (i.e. the x,y,z co-ordinates of the surface and an optional texture map) of the terrain in the stereo pair (left).
 

The functional relationships between the workstations different software components are summarised in the following UML diagram.

Functional relationship between different software components - UML Diagram