Re: [Gimp-user] Having trouble creating transparent background

[Steve Kinney <admin pilobilus net>]

On 01/31/2017 06:33 PM, Accordeoniste wrote:
> I took a photo of me standing against a wall. The wall is pale yellow in color.
> It's hard to describe its texture, but  it isn't smooth, if that makes a
> difference.
>
> To create a transparent background, I took the advice of an online tutorial.
> First I added an alpha channel with Layer / Transparency / Add Alpha Channel.
> Then I selected the background with the Fuzzy Select tool. Then I pressed the
> delete key. The result was a mostly transparent background. There's a moving
> black and white line that borders my image. There are also moving
> black-and-white striped areas near my arm, and random white spots that sparkle.
> I tried using the eraser tool to remove the black-and white patches, lines and
> spots, but after erasing them, they re-appeared. Another time I followed this
> procedure, the white areas were either more pronounced or there were
> orange-brown streaks bordering my photo.
>
> Is there a way I can efficiently remove the white debris in GIMP, whatever it's
> from, so the background is completely transparent, without having to take
> another photo of myself against a different background, e.g. a white one? It's
> important that I get this right as I want to place my photo against a more
> dramatic background image to display on my website. I'd be grateful for any
> suggestions.

No problem.  There is no one-step push button method; cleanly separating
an object in a photograph from its background always takes some
tweaking.  But we have ways:

https://www.youtube.com/watch?v=xEfRVEC2cmY

True confession:  I almost started to write instructions before I
thought to look for a video tutorial.

Handy household hint:  While painting bits of your foreground object in
and out of visibility, you can quickly switch from white to black by
putting the brush over a visible or transparent part of your image in
progress, hold down the Alt key, and click once.  That will set the
brush color to whatever was under the center of the brush when you
clicked on the canvas.

All done?  Crop your image with the Crop tool, save it as an XCF file so
you can make modifications later if desired, scale it to suit and Export
to PNG.  Viola.  (I would take care not so Save the scaled version as
XCF, which would over-write and destroy the original scale image you
worked on.)

:o)