(04-10-2017, 05:33 AM)Michael Wrote: ...snip... I really need something that can detect straight lines and I'm beginning to think that might be me.
In case you ever come back, I think you are correct there.
It is the batch requirement which is mostly the problem.
Once you make your mind up that each image has to be hand processed, it is then a search to find an efficient method.
I suggest using mostly standard Gimp with the exception of ofnuts plugin to straighten an image
and download ofn-layer-straightener.zip
unzip and put ofn-layer-straightener.py in your Gimp profile C:\Users\your-name\.gimp-2.8\plug-ins
Look at using key shortcuts for as much as possible https://docs.gimp.org/en/gimp-concepts-shortcuts.html
I set up A = python-fu-ofn-straighten S = Remove Alpha D = AutoCrop Image The others already have assigned shortcuts. screenshot: http://i.imgur.com/zcZXzpz.jpg
The procedure might be:
Open the image.
F to get the free select tool - then make your selection.
ctrl-C copies the selection
shift-ctrl-V pastes as a new image. screenshot http://i.imgur.com/rGF0bVP.jpg
In the new image
B selects the path tool - draw a path in along an edge
A applies the straighten plugin screenshot: http://i.imgur.com/e46dN4b.jpg
to tidy up - not absolutely necessary - if exported to a jpeg you lose transparency anyway.
S removes any transparency from the rotate
D removes the excess layer boundary screenshot: http://i.imgur.com/thneHkv.jpg
Export image as png or jpg or tif - whatever you use.
repeat for next.
Hope you are using a stand for all this (unlike my hand help photo)