Re: [Gimp-user] selection by value threshold

[Mitti Mithai <mittimithai gmail com>]

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.

On Tue, Jul 11, 2017 at 3:10 PM, Carol Spears <carol spears gmail com>
wrote:

> On Mon, Jul 10, 2017 at 2:33 AM, Mitti Mithai <mittimithai gmail com>
> wrote:
>
> > I've never had to to this with gimp yet, but I need to make a selection by
> > value threshold (I want to "cut out" stars that are hitting saturation in
> > my image with values of 64k)...I can't quite seem to figure out how to do
> > it.  Does anyone have any advice?
>
> Image -->Colors-->Components-->Decompose has options to decompose by HSV
> and HSL.  Perhaps the Saturation layer would be helpful?
>
> If you have an example image, after decomposing, you could select by the
> color of gray that your saturation would be.
>
> Interesting problem....
>
> carol