W. Watson wrote:
> I have a fish-eye image (bmp file, 640x480, b/w) of my property. It
> shows the
> complete horizon with trees, houses, poles, etc., plus the sky. I would
> like to set
> all the values in the image below the skyline to a specific value, say,
> 40, and
> thereby create an image mask for my application. I've been told there
> are two
> programs in linux, http://www.python.org and Gimp, that allow one to perform these
> operations.


I think it's ImageMagick and Gimp.

Gimp
> does not import grey scale files, but I can get around that with
> convert. Can someone
> give me an idea how I can use either of these programs to create the
> mask. I'll
> likely want to set the values above the skyline to zero too.


Me cannot help, but here are some Gimp resources.
http://www.futuredesktop.org/#office

Gimp people are on:
news://comp.graphics.apps.gimp

Cheers,
// moma