02-02-2019, 10:18 AM
Quote:...Then I review the image and find a color not in use in the target image, say HTML color h1cf905..
All depends on the image but generally with Gimp 2.8 that will be a difficult find. There will be elements of #1cf905 in the colours. This a comparison before/after 2.8 c2a leaving a semi-transparent image.
If you ever upgrade to Gimp 2.10 the GEGL c2a has some extra controls that might make an improvement.
However as Blighty points out there are other ways and depending what you are doing (one-off / many similar layers) a layer mask is non-destructive and give plenty of control by painting transparency in/out or there are plugins to help. Ofnuts has one ofn-erase-background.py about 5 down here: http://sourceforge.net/projects/gimp-too...s/scripts/