Dear Helpers

I have recently updated to Gimp 2.10 (under Ubuntu 18.04). I use Gimp extensively for processing photos. One very common problem is having the photo tilted by a few degrees. It is easy to straighten it using the rotate tool or the new way via the measurement tool. In Gimp 2.8 it used to be very easy to crop off any excess using the autocrop tool. However nothing I have tried works that way in Gimp 2.10.

I created a small image to demonstrate what happens. On the left is my "photo" a bit out of whack;). IN the middle is a screen shot of the image after rotation. The third is what I would like, which autocrop under Gimp 2.8 would create. In GImp 2.10, if I "crop to content" (under Image menu item) then I get an error message saying "cannot crop because the image is already cropped to content". Using "crop to selection" then the grey border inside the yellow dotted lines disappears which is what one would expect. I would like the crop to be such that it crops off the outer section plus all the transparent sections.

I have searched for an answer but could not get the results as described in http://www.gimpusers.com/forums/gimp-user/20922-crop-to-selection-not-working

Any help would be much appreciated:)

Thanks

Margaret

Apologies, as usual not paying enough attention to what you want as an outcome.

You could try this plugin StraightCrop. Comes from the now defunct gimp-plugin-registry site. Tried in Kubuntu 16.04 Gimp 2.10.8 flatpak so should work on your 18.04 installation.

The plugin attached, unzip and put in your Gimp user profile ~/.config/GIMP/2.10/plug-ins

The permissions should already be set but check for executable anyway.

In action, make a straight path then menu Image -> Transform -> Straighten & Crop

rich: www.gimp-forum.net

Thanks so much for solving my problem:) The answer was there under my nose all the time but I didn't register its importance until I read your reply. In both "straightening using the measure tool" and "straightening by corrective rotation", then using clipping with the "crop to result " option gives a result in which "Image: crop to content" gives what I want.

Thanks so much for your help:):)

Apologies, as usual not paying enough attention to what you want as an outcome.

You could try this plugin StraightCrop. Comes from the now defunct gimp-plugin-registry site. Tried in Kubuntu 16.04 Gimp 2.10.8 flatpak so should work on your 18.04 installation.

The plugin attached, unzip and put in your Gimp user profile ~/.config/GIMP/2.10/plug-ins

The permissions should already be set but check for executable anyway.

In action, make a straight path then menu Image -> Transform -> Straighten & Crop

rich: www.gimp-forum.net

Thanks so much for solving my problem:) The answer was there under my nose all the time but I didn't register its importance until I read your reply. In both "straightening using the measure tool" and "straightening by corrective rotation", then using clipping with the "crop to result " option gives a result in which "Image: crop to content" gives what I want.

Thanks so much for your help:):)

It is the alpha channel which interferes.

1. Using the Gimp 2.10 measure tool for straightening, recommend set "Clipping" to clip.

2. Apply that and then consider the background colour. If it is white as your example the skip the next. Photographs often have an off-white value .

3. If needed, colour-pick the background color and then Layer -> Transparency -> Remove alpha channel. That should give a solid uniform background.

4. Apply zealous crop or crop to content.

A better way for the background colour might be using the resynthesizer/heal-transparency plugins. (***don't use*** the registry-plugin deb package for this, grab them separately) then remove alpha.

rich: www.gimp-forum.net

Thanks for the tip about resynthesizer. I downloaded and compiled it and it works:):) Something I use quite frequently :)

:):)