Re: [Lensfun-users] Question re CA correction

[Torsten B. <br...@ph...>]

Hallöchen!

chris shea writes:

> [...]
>
>   * Using Magick, I split the image into red, green and blue
> channels. I use the TCA Vr and Vb parms (* 100 to make them
> percentage values) to resize the red and blue channels. I then
> re-combine the unchanged green channel image with the resized red
> and blue channel images.

Have you tried the reciprocal values?  Because Lensfun's polynomial
does not transform the distorted to the undistorted image.  Instead,
it calculates for every undistorted pixel where to look up its value
in the original (distorted) image.

Furthermore, you must transform the image in the original colour
space.  sRGB is only applicable for cameras that can create
JPEGs *only*.

> [...]
>
> I also haven't figured out where to find the latest version of the
> DB so an answer to that would also be appreciated.

Its at http://wilson.bronger.org/db/version_1.tar.bz2

Tschö,
Torsten.

-- 
Torsten Bronger