On 2011-01-03 7:31 AM, dmg wrote:
field of view changes when the image is in landscape mode might have
interesting repercussions during optimization.
I wonder if a better solution would be to scale with respect to the
corner of the frame.
This is something that new users stumble over. There should only be one FoV for
a lens.
We need to decide on shortest, longest, or diagonal.
I got curious about how radial correction is computed and did a small test.
[snip]
It looks as if, in the case of the 2 rectangular images, there is
scaling, but not in the squarish image.
In the code, the scale of the image is normalized as 1/2 the smallest
of dimensions. This means the image is not scaled with respect to the
longest dimension, but it is scaled with respect to the shortest
dimension. Now, this example is a bit extreme because the ration
width to length is 2. But even if it was 1.5 (as with 36mm cameras)
the different is significant.
I suspect helmut did this because most people shoot panoramas with the
camera in portrait mode. This way the "horizontal" field of view,
remains unchanged after the correction has been applied.
I was sure it was the longest dimension used. I had to go back and check. You
are right it is shortest. I thought that if shooting portrait and instead of
using the minimum number of images needed to make a pano a whole bunch of images
used and cropped down narrow strips of only a few degrees each the same abc
values could be used. But this is not the case.
--dmg
---
Daniel M. German
http://turingmachine.org
--
Jim Watters
http://photocreations.ca
--
You received this message because you are subscribed to the Google Groups "Hugin and
other free panoramic software" group.
A list of frequently asked questions is available at:
http://wiki.panotools.org/Hugin_FAQ
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to
[email protected]
For more options, visit this group at http://groups.google.com/group/hugin-ptx
