[sane-devel] Dusting-off with the Gimp/Coolscan2

[Laurent-jan]

Georges Roux wrote:
> Can you explain more, may be on your site, with exemples
> please
> 

Brightness, contrast and gammacorrection are concerned with the colors 
of the image. See chapter 11 of my FAQ.

Dusting-off is concerned with obscured pixels. Basically there are two 
problems with dusting off:
1- Where is the dust
2- You cannot see what is under the dust

1 is (partly) solved by the IR-scan. Ideally, the IR scan should give a 
black/white image with only the dust on it. This is never the case: some 
dust is grey, some of the other colors bleed through to the IR-channel. 
I still got some work to do here. You can "cut-out" the dust and make 
holes in the image.

2 is solved by interpolating the pixels around the hole. Andreas used a 
simple interpolation method that works well for small holes. I renamed 
his filter to "fill holes" under GIMP. You can test it without a coolscan:
- take an image
- add an alpha-channel
- cut a small strip away
- start filters/enhance/fill holes
(of course you need to install the filter first)

ljm


-- 
(c) ljm @ xs4all . nl.  No part of this copyright message may be
reproduced, read or seen, dead or alive or by any means, including
but not limited to telepathy  without the benevolence of the author.