Distortionizer

Maintained at https://github.com/OSVR/distortionizer

For details, see http://osvr.github.io

For support, see http://support.osvr.com

Distortionizer tool that allows estimating the optical and chromatic distortion of HMDs and a shader that uses the measured parameters to correct such distortion.

Instructions on how to get it to build and run in VS

1. Download and install latest version of Qt (with openGL)
2. Download and unpack latest version of GLEW
3. Open CMake and navigate to distortionizer directory
4. Add path for build directory like /distortionizer/bin
5. Click "Add Entry", add CMAKE_PREFIX_PATH of type STRING with the value containing the location of Qt OpenGL directory and Glew directory like C:/Qt/Qt5.4.0-gl/5.4/msvc2013_opengl;C:/glew
6. Click "Configure", and choose the right generator (probably Visual Studio 12 2013).
7. If there is an error, the "Generate" button will not be available. Just having red entries doesn't mean it failed - you'd see an error message down below. If it did fail, you'll need to fill in more entries, depending on what it failed to find. For example:

• For Qt5Widgets_DIR specify like (adjust for your path) C:/Qt/Qt5.4.0-gl/5.4/msvc2013_opengl/lib/cmake/Qt5Widgets
• For Qt5OpenGL_DIR specify like (adjust for your path) C:/Qt/Qt5.4.0-gl/5.4/msvc2013_opengl/lib/cmake/Qt5OpenGL
• For GLEW_DLL specify like (adjusting for your path) C:/glew/bin/Release/Win32/glew32.dll

8. Once you've gotten it to successfully configure, click "Generate" to make the VS solution in the build directory.
9. After you open solution, right click on distortionizer-calibration in VS in Solution Explorer widget and select "Set as Startup Project"
10. In menu header, click on Project -> Properties (or Alt+F7) and in "Configuration Properties" -> Debugging set "Environment" to something like PATH=$(PATH);C:\Qt\Qt5.4.0-gl\5.4\msvc2013_opengl\bin otherwise it will complain about missing Qt5OpenGL.dll file

Instructions on how to use Distortionizer

Distortion estimation for HMD using K1 (quadratic) term

The program always runs on the last screen, full screen

Click with the mouse in the left eye to locate center

Keyboard controls:

• r/R: Increase/Decrease distortion in R+G+B
• g/G: Increase/Decrease distortion in G+B
• b/B: Increase/Decrease distortion in B only
• S/L: Save/Load state from JSON config file (HMD_Config.json by default)
• Left,Right,Up,Down: Move the center of projection by one pixel
• f/F: Toggle fullscreen on/off
• c/C: Reset center of projection
• v/V: Reset distortion values to 0
• ESC/Q: Quit the application

To judge the results, pull the HMD out of DirectMode so that it shows up as a second display. Put it into Landscape mode. Move the distortion window onto the HMD's display and then use F to toggle fullscreen on. Look through the HMD and adjust the values to make red, green and blue line up and to make all of the lines straight. This is an optimization in a high-dimensional space, so be prepared for some frustration.

License

This project: Licensed under the Apache License, Version 2.0.

angles_to_config

This is a stand-alone program that provides a more principled approach to distortion correction than the "adjust until it looks right" method described above.

It reads in the results of measurements of display positions with respect to angles from the eye position when looking through the display and produces either one mesh (for mono) or three (for RGB) distortion maps.

polynomial_fit

This is a stand-alone program that takes in a polynomial that maps from millimeters on a display to the tangent of the angle that a pixel at that location is visible at. It computes radial distortion coefficients and a display descriptor including the horizontal and vertical fields of view.