Transform types
This page lists what exactly OCVWarp does. It reads a video, transforms it in one of the ways listed below, and writes it back as a video file.
The latest list of transform types is at transformtype.txt.
The transform type parameter in OCVWarp.ini can have the following values.
For example, this scene from Paul's 360 youtube video
can become something like
The view angle can be changed with keyboard commands h, u, k, m or with the ini file anglex angley parameters. The above view was with anglex=0.0, angley=-90.0 So, changing anglex to 90.0, we get the following.
and so on. This sort of angular fisheye mapping is explained very well on Paul's website.
In a 180 degree fisheye video, the field of view is restricted to 180 degrees, or a hemisphere. Only half of the above scene would be visible, like the image below.
This may be more recognizable as a 180-degree fisheye or fulldome master image if a circle is overlaid over it, like below.
This does the reverse transform of 0. For anglex = angley = 0, a 360 degree fisheye looks like this,
and after transformtype = 2, this brings back an equirectangular 360 video like this -
This does the reverse transform of 1. For anglex = angley = 0, a 180 degree fisheye looks like this,
and after transformtype = 2, this brings back an equirectangular 360 video like this -
Here, the bottom half can be recognized as the bottom half of the original 360 scene. Maybe this can be done in a better way :)
This does a similar transformation as TGAWarp - this requires a map file similar to the included EP_xyuv_1920.map. The 180 degree fisheye obtained with transform type 1 would become
This is equivalent to doing a type 1 transformation followed by a type 4 transformation, as above.