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Philippe Gac wrote:<br>
<blockquote type="cite"
cite="midLPBBLPCDPAOMGEINOAHFEELGDOAA.tech@ediphi.org">
<pre wrap="">hi all,
Stitching scanned, "flat" images
</pre>
<blockquote type="cite">
<pre wrap="">The proper way to do this with PT is to use the offset variables keeping
y,p,r constant just optimize d & e
</pre>
</blockquote>
<pre wrap=""><!---->and y, p, r should be set to a very small value
OK
Now, what about translated views for rectilinear projection of a front plane?
you have to set y, p, r to their real values
can the offset variables d and e do the job correctly?
I'm not sure this can be done even if the picture is taken orthogonally to the plan</pre>
</blockquote>
This should work OK but only if a/b/c are all zero. If a/b/c are not
zero, you will get distorted images for large d and e. This is because
d and e shift the lens center, which shifts the center of the lens
correction polynomial. If you require nonzero a/b/c to correct lens
distortions, then you need to make two passes. First correct the lens
distortions by generating new images with y/p/r=0 and a/b/c/d/e as
needed. (Probably d/e=0 in this case.) Then make a second pass to
stitch the corrected images using d/e to do the shifts for alignment.<br>
<blockquote type="cite"
cite="midLPBBLPCDPAOMGEINOAHFEELGDOAA.tech@ediphi.org">
<pre wrap="">
What if the pictures are taken with vaious angles to the plan?
this happens systematically because of the imprecise positioning and intentionnally when you want to avoid the flash
reflection on the plane.</pre>
</blockquote>
Sorry, won't work, or at least won't work very well. The Panorama
Tools imaging model assumes that the world is painted on the inside of
a sphere, with the lens entrance pupil at its center. The math for
this model also handles a few other special cases. One of those
special cases is translation in a plane, perpendicular to the line of
sight, parallel to a flat subject, using a perfect rectilinear lens.
Most everything else is an approximation and you will get stitching
errors.<br>
<br>
--Rik<br>
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