At 09:40 19/01/00 -0600, Jon Winters <[EMAIL PROTECTED]> wrote:
>
>There exists so called 'stiching' software that is supposed to do this
>sort of thing.  I think I remember seeing something from Ulead but I
>haven't used it.

I read some reviews of a number of different stitching programs/plug-ins a
while ago (none for Gimp...). If I come across it again I'll post a mention
of the names (it may take a while to find them). A similar effect is
achieve in Quicktime VR, giving you a panorama that is actually a ring -
you can keep going round and round.

Some of the software does it all automatically, by analysing the contents
of the pictures to work out which bits correspond. The more accurate ones
seem to require the user to indicate the corresponding bits.

>You might try using the transform tool to shift perspective so that the
>component images match up.  
>
>Make a big canvas.
>Paste in the starting image.
>Paste in the second image near the first.
>Then select the second image and shift its perspective so that it matches
>up to the first.  
>
>So on and so forth until they all match.

Trying to achieve seamless results manually is almost impossible, but it's
fun to try. With all the errors (translation, image plane rotation,
perspective distortion, exposure differences, moving objects), you have
your work cut out for you. If you set the camera up on a tripod, lock
exposure settings and take photos at fixed angles, you can minimise some of
these problems. I gather from the fact that there were 13 photos, that they
probably aren't fixed-angle.

>I'll put my camera on a tripod tonight and try it out.  Over the next few
>days I'll put my camera on a tripod and try this out.  I'll post results
>to the list.
>
>I don't know if you'll be able to get the images to match at all on the
>edges.  Distortion might be too great.  You may need some overlap to get
>things to look nice.

For a panorama made this way, you are trying to simulate a curved image
plane with a set of flat ones, and so straight lines end up with kinks or
offsets in them at the sub-image boundaries. The stitching software warps
the individual images, preferably with a reasonable overlap, to avoid the
perspective distortion, and also to account for slight rotations,
translations (and scalings?). The warping is not a planar "perspective"
warping, but more of a fish-eye effect - the middle of the sub-image needs
to stay almost the same, but the distortion increases towards the edges.

The results I saw from the stitching software looked pretty good,
especially across the middle of the combined image. It tended to fall apart
a bit at the top and bottom, where the joins became more obvious.

>Interesting question. :-)

Indeed. I've harboured a desire to mess around with writing software to do
this for some time (where time is the problem - and possibly knowledge and
skill).

Good luck with your respective efforts.

Regards,


Ian

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