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I have spent the last 6 HOURS trying to do one simple thing, transform a rectangular image into a right triangle without distorting the pixel placement vertically. I have used EVERY transform tool, looked through every filter, and for the life of me I cannot figure out how to do this. So PLEASE if anyone can tell me if this is possible, and if so how I can do it, it would be greatly appreciated.

To me your desctiption "without distorting the pixel placement vertically" means this: https://i.imgur.com/fq2qCGq.jpg which is a simple (selection) crop, however I suspect that you want to compress all the vertical pixels into whatever space is available . Is that correct ?

(10-16-2020, 07:13 AM)rich2005 Wrote: [ -> ]To me your desctiption  "without distorting the pixel placement vertically" means this: https://i.imgur.com/fq2qCGq.jpg which is a simple (selection) crop, however I suspect that you want to compress all the vertical pixels into whatever space is available . Is that correct ?

Circled in red is what I don't want to happen. I want the pixels to be vertically locked. In this example I used the perspective tool, but I have attempted to use every other transform and distort tool to accomplish what I want.

To put it as plainly as I can I do not want the pixels to move up and down, I want them to compress left and right.

Is this what you want ?
[attachment=5074]

(10-16-2020, 09:37 AM)denzjos Wrote: [ -> ]Is this what you want ?

YES OMG YES, how did you do that cause the only method I found was to do it manually pixel by pixel

I also tried almost everything in gimp and also find no solution, so I tried to do this in Paint.net 4.2.13. I have a Shellout to this program in my gimp filter menu. I found that it is possible with (in the Paint.net menu): Effects/Distort/Quadrilateral Reshape. Just use the upper sliders. It could be possible that there is such a plugin for gimp, but I have no clue.

Gave up (1) spliting into columns and scaling using scripts (2) the Gmic plugin cartesian deform (must be possible but I can not figure out the correct equations)

Not Gimp, ImageMagick, https://imagemagick.org/  and from this page https://im.snibgo.com/sh2sh.htm


gives this before / after

[attachment=5084]

It does require a trim along the diagonal.

(10-17-2020, 03:33 PM)rich2005 Wrote: [ -> ]Gave up (1) spliting into columns and scaling using scripts (2) the Gmic plugin cartesian deform (must be possible but I can not figure out the correct equations)

Not Gimp, ImageMagick, https://imagemagick.org/  and from this page https://im.snibgo.com/sh2sh.htm

Code:

magick  in.png -fx "p{j==0?0:i*h/j,j}"  out.png

gives this before / after



It does require a trim along the diagonal.

Thank you SO MUCH this has been driving me nuts for 2 days now. Now I can get back on track for the project I'm trying to finish.