Re: [Gimp-user] irregular cropping

[Steve Kinney <admin pilobilus net>]

On 11/4/18 9:47 PM, Ward Ricker via gimp-user-list wrote:
> I downloaded GIMP in order to crop around an odd shaped picture, i.e.,
> remove the white background around an object in a rectangular picture so as
> to leave an odd-shaped image.  I have not studied how to use GIMP.  Since
> this is the only thing I wish to use it for I am simply following the
> third-party instructions from the website where I found out about it, but
> they are simple.   I am:
>
>                 Opening my image in GIMP

etc.

I would suggest:

Open your image in the GIMP.

Find your picture in the Layers dialog, right click the thumbnail, and
click Add Alpha Channel.  (That enables transparency.)

Find and activate the Magic Wand tool, a.k.a. contiguous select.  Click
on the background you want rid of.

Then, then do Control-x, or Edit > Delete.

This should remove the unwanted border area, leaving blank space
represented by a two-tone gray checkerboard on the screen.

Then do File > Save as, and enter a name for your edited file, ending in
.png.  Save the image and there ya go:  The result may be good enough
for your purpose, or you may have to use more "manual" techniques.  But
at least it's a start.

For more precise results, the "Lasso" tool used as you describe should
work well; but remember to do Select > Invert before deleting, or you
will remove the content you want to keep, and keep the border you want
rid of.  And always make sure the Alpha channel is on, any time you want
to make something transparent.

:o)