PanoTools:
Re: My attempt to eliminate vignetting effect
Erik Krause 2004-Nov-29 20:11:43
On 28 Nov 2004 at 22:54, JD Smith wrote:
> The big technical hurdle will be that currently enblend knows nothing
> about the original, pre-transformation image coordinate system.
[...]
> Thoughts?
I fully agree. May be it is not needed for enblend to know the
orignial coordinate system. Panotools could either provide another
channel with a mask (similar to the levels mask Valeriy uses)
indicating the amount of correction. This mask could undergo the same
transformation as the original image. (I think nona had a feature
like this).
Or better: In a separate TIFF tag there could be some data that
allows enblend to calculate the displacement by itself.
Perhaps it isn't even necessary to know the transformation geometry.
If you calculate the difference between two images in an overlap
region you should clearly see both vignetting and brightness
differences.
If you take a low spatial frequency version there should be almost
the same difference in the whole overlap if there is a brightness
difference only. There should be a gradient from negative to
positive values if there is vignetting. A correction mask could be
estimated from this gradient.
best regards
--
Erik Krause
Ressources, not only for panorama creation:
http://www.erik-krause.de/
Read panotools at GMane:
http://news.gmane.org/gmane.comp.graphics.panotools
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