Dewarping Algorithms and Lens Parameter Information


I saw a reference to this paper by Paul Bourke on the official forum “Converting dual fisheye images into a spherical equirectangular projection

The author also wrote a number of interesting articles, including “Converting a fisheye image into a panoramic spherical or perspective projection” and “Tilting fisheye images for variable dome orientations

While this used by THETA developers right now as the THETA does not output a dual-fisheye image, it’s likely that the THETA V plug-in SDK will allow a dual-fisheye image to be saved internally and that the internal Android OS can be used for image processing inside of the camera.

If the plug-in application has this requirement, there could be a need to convert and image either from dual-fish or single-fish and dewarp it.

To convert a dual-fisheye image into an equirectangular image, the developer needs the lens parameter information of the THETA V to compensate for the specifics of the lens. Without this information, the stitch will not be perfect.

Currently, there is no way to get the lens parameter information. However, if we organize feedback from developers on the need for lens parameter information, I can present this information to Ricoh for consideration. IMO, the starting point to get this info released under NDA is to first show demand.

We may hear more requirements from developers once the plug-in SDK comes out of closed beta. In the meantime, please put your feedback below.

Ideas from Paul Bourke’s Articles


90 degree tilt

Dual-fish to Equirectangular


Changing Perspective


This ability to control the output from the THETA V is a good example of the exceptional flexibility of the THETA V for developers.