Hello,

I would like to report that I've localized and solved all my problems.
Problem with fov-focal length correction was due to the use of individual
crop parameters for each image. In this case PTGui seems to use a default
crop diameter Dcrop for this conversion. As far as I understood, it's the
value which binds theoretical fov to theoretical focal length.

Moreover, I found that my problems with radial correction were connected to
the incorrect fov estimation, as it is only the PTGui interface which
calculates f from fov as stated above, but for radial distortion correction
one should use the value calculated from equidistant projection.

Also, I found out that the polynomial in the forward direction should be
used in projection, and solving the polynomial equation - in backprojection
procedure.

In all the rest my statements were OK.

I'll just leave it here for next generation of developers :)