https://vimeo.com/64336199
Just discovered this yesterday.
This gives no noticeable curvature between points .
(Sorry cudnt embed video)

It's cool, but not suitable for precise transformations because of aliasing.

Krita's free transformation tool also allows you to change perspective, but it works by flipping whole planes, so it's rather hard to control.
Gimp's perspective transformation tool allows you to just drag each corner one by one. In fact, Krita's perspective grid allows you to drag the corners too.

There's actually a feature request for being able to control the perspective transformation by dragging the individual corners too:
https://bugs.kde.org/show_bug.cgi?id=300799
If you really want that, you could go vote for the wish.

Hi aalex ,
You are right, the curvature doesn't completely go away and the aliasing exists as well. I just thot it shud be possible for the warp tool to get us close. But not good enuf for precise work.

Hi valerievk ,
I shall vote for it, thanks.

aalex wrote:It's cool, but not suitable for precise transformations because of aliasing.

I don't get such aliasing with it. What interpolation algorithm are you using? What you are showing above looks more like the "nearest neightbor" used for preview than like the bicubic or sinc/Lanczos you can use for the actual rendering.



I'm not saying that you don't get any aliasing or blur... there will always be some since it is a bitmap editor.

Ofnuts, it's interesting. How did you get that result?
Free transform quality is really good (at least in 2.7.x), but I noticed, that interpolation method has no effect in the Warp mode.