Gimp 2.6.6 on Ubuntu Linux 8.04.
Scanning using VueScan Professional 8.5.20 with an "Epson Perfection
4490 Photo" scanner. Color profile has been built for the scanner using
available photo color target from a well-known German source (can't
Almost all my scanning is of postage stamps and related items --
scanning the actual physical objects, not photos of the objects.
The stamps are currently scanned on a black background (for lack of
other color possibilities; the final goal is on a black background).
After scanning, the background is selected and turned to 100% black to
have greatest contrast for the object. When a stamp has a postmark that
crosses the edge of the stamp paper, the color of the postmark (usually
dark or black) is very close to the color of the scanning background and
thus when the background is selected, the selection "leaks" and
"follows" the postmark onto the stamp. We have to manually exclude
those "leaks" from the desired selection area.
To be able to select the background (for change to 100% black) without
any "leakage" of the selection onto the stamp objects AND without ANY
non-black color artifacts remaining after changing the selection to 100%
We have tried scanning on many different non-black background colors and
surfaces, but there are always some extreme-edge color artifacts
remaining ... leaving a sort of "halo" effect around the stamp object.
Some of this could be attributable to the particular model of scanner,
though every scanner I have ever owned had a similar problem to a
greater or lesser degree. The width of the "halo" usually depends upon
which side of the object it is on vs the direction of travel of the
In television broadcasting it is extremely common for somebody to stand
in front of a "green screen" and for the green to be electronically
replaced with some image or video, etc. (For example, the weather
person standing in front of a weather map.) It is rare to see a green
"halo" if everything has been done correctly and if the person is
wearing the correct type of clothing fabric.
Is there some Gimp method or plug-in or other tool that will better
handle this type of use?
Recently poster Ron Guilmette discussed his use of
"Darla-PurpleFringe.scm" plug-in to remove an artifact caused by a
digital camera and subsequent processing.
Is there something like that which can be used to remove a color "halo"
that results from using a "green screen" approach to scanning? (I would
likely have to select different colors of "green screen" so that such
colors are not included in the design of the postage stamp.
Any advice would be appreciated.
gimp-user-list mailing list