On 10/15/05, Felix E. Klee <[EMAIL PROTECTED]> wrote:
> At Fri, 14 Oct 2005 13:48:59 +0200,
> Felix E. Klee wrote:
> > I want to bend an grayscale image's gray level curve so that three
> > input levels are turned into three output levels.  For all six levels
> > I have the precise values, for example acquired with the color picker
> > tool.

> > Any suggestions?
> Being desperate, I fired up Micrografx Picture Publisher 5.0a, an old
> Win 3.1 program.  It's capabilities for doing color correction are quite

> Now, although Picture Publisher 5.0a is still a very nice tool, it does
> have a number of disadvantages, especially when it comes to handling
> modern file formats.  Also, it - of course - doesn't run natively under
> LINUX.  That's why I try to do more and more tasks with the Gimp, and
> that's why I still would like to hear about a simple solution for my
> problem with the Gimp.

This sounds interesting, although I wish I knew what a gray level
curve was (is it that histogram-like thing that you get on some
cameras that shows you how much the value is in the various regions of
the picture left to right?).

If there is a numerical formula or procedure you can think of where I
can give you any random pixel, and you can use that pixel's value,
(and maybe position or some other data that should be obtainable from
that pixel), the three input values, and three output values, I can
imagine a plug-in being created.  I can't think of any such thing,
unfortunately.  Otherwise, my next guess would be resorting to a
bogo-sort-like "algorithm", which would take years to come up with a
result for one image.  I'm sure someone else can do better, obviously.

Is there a display function/filter/tool/plug-in/script-fu/etc for the
grey level curve in GIMP though?

IIRC, in GIMP 1.x, there was a plugin that would, at the least, I
believe, normalize the grey curve (although I may be wrong)...
appraently the plug-in is no longer necessary for it's purpose in GIMP
2.x, although I don't know.

What about the Layer | Colour | Curves dialgoue thingie (Colour |
Curves in GIMP 2.3.4)?

 - Just my two cents
 - No man is an island, and no man is unable.
Gimp-user mailing list

Reply via email to