[ptx] gimp/krita help in removing artifacts

[Bruno Postle]

On Wed 14-Dec-2005 at 17:27 -0500, Michael Galloway wrote:

> this is a bit off topic perhaps, but i could use a bit of help 
> with gimp/krita in managing layer masks to mask out stitching 
> inconsistancies. i was working thru this tutorial:
>
> http://homepage.ntlworld.com/j.houghton/pttute.htm

Not off-topic at all, this should be a hugin tutorial since it isn't 
very well documented...

You can control the position of seams by masking out areas you don't 
want with an 'alpha channel'.

There are two ways of doing this; modify the original photos before 
loading them into hugin, or modify the 'multiple TIFF' output from 
nona before running enblend manually.  I find the first technique is 
simpler.

Either way, you need to save as a file format that supports alpha 
channels such as PNG or TIFF (JPEG is no good here).  Note that all 
the files in a project need to be the same format - If you mix PNG 
images with alpha channels and JPEG photos, nona fails silently and 
produces no output.

To create an alpha channel in the gimp, select Layer -> Transparency 
-> Add Alpha Channel.  Mask out the areas that you don't want with 
the 'eraser' tool or select and delete with the 'lasso'.  
Erased/transparent areas are shown with a grey 'checkerboard' 
pattern.

That's it, other than that you can just follow John Houghton's 
tutorial for PTGui.

-- 
Bruno