My compliments on the many features of the GIMP program.
But for the technical activity that I carry out I find myself some technical documents that have been appropriately scanned.
With the effect that they are rotated with respect to the X-Y axes and you have to try to make rotations by hand.
It would not be advisable to insert three points of a title block or a square to have the correct rotation.
Not too clear what the actual problem is. Two ways to fix rotations:
- Using the Rotate tool:
- Set to
Correctivemode - Make it display guides (
Number of linesfor a grid) - Acting on the canvas will rotate the guides and not the image
- Align the guides with whatever should be horizontal/vertical
- Apply the rotation
- Set to
- Using the Measure tool
- Measure something along a feature of the image that should be vertical/horizontal
- Hit the
Straightenbutton in the Tool options
Unless you are talking about perspective distortion (but this doesn’t happen with a scanner, just with photos taken with an angle), in which case the Perspective tool also has a “Corrective” mode.