How to scale an image RATIOnally?

[Ofnuts]

(07-26-2018, 10:04 AM)neverwind Wrote: Hello,

I've been struggling with a rather simple task for a while.
I do have an image which I want to scale in such a way, that the center of the image is less or not affected at all by the scaling than the edges.
I'll try to give a simple example with pixels, since I don't really know how to describe the effect:

1. We have an image with a 5 pixel width
2. We scale the image horizontally
3. The center column of pixels remains unaffected (not stretched)
4. The -1 and 1 columns of pixels get doubled (stretched)
5. The -2 and 2 columns of pixels get tripled (stretched more)

Is this achievable with Gimp and if so, can someone please give me a clue how to do that?

Many thanks,
Bobby

This looks like lens distortion, so see if Filters>Distorts>Lens distortion does it. Otherwise, Filters>Distorts>Whirl and pinch.