Re: [Gimp-user] selection by value threshold

[Carol Spears <carol spears gmail com>]

On Wed, Jul 12, 2017 at 3:08 AM, Mitti Mithai <mittimithai gmail com> wrote:

> Somehow I neglected to mention that I am trying to do this in gimp 2.9.
>
> Indeed I could do something like convert to grayscale and then select, but
> right now I can't numerically specify the range of 16-bit values that I
> want to be selected.
Select By Color can be used, but I can't tell how the selection is working
> in gimp since the threshold appears to suggest it is working on the 8-bit
> image on screen.  I can't quite suss out if 16-bit is fully supported from
> python-fu in 2.9...if someone is confident it is I could write this as a
> simple plugin.
>
> I confess, I don't understand the differences between 16-bit and 8-bit
images other than certainly one has a lot more information than the
other....

I do know something about gimp-2.9.  Neither script-fu nor python-fu are
being "maintained".  An example of this is that it is no longer possible to
convert an image from RGB to GRAY due to an extra color profile parameter
required by GIMP.  And I read of similar problems with script-fu (although
that might be a new notation for layer modes).

On the layer modes!  That is where gimp-2.9 is crazy different than all
other GIMP!  Color erase has performed miracles for me.  As you work
through solving this problem of yours, take a look at these new layer
modes.  The answer you need might be in there.

carol