Stitching together two panoramas to make a full 360 panorama

[spoo...@gmail.com]

Hello !

Possibly a silly question - that has a simple answer (that I haven't just figured out).

I have been doing some crowd images from various games, and mainly do them to max. 200-260 degree views - due to the fact that once you are taking an image inside an arena.. the people at the far end and people behind you require different focal lengths to capture them in High Res. So - would PtGui be able to stitch two panoramic images together, lets say one taken with 135mm focal length and the other at 70mm focal length - and then stitch these together into one single panorama from the two different images?

I guess it would have the two images with their own lens settings - and you would need to create Control Points between the two images..

There are plenty of examples online of such images - but nowhere can you find explanations on how they have done it :-) Maybe because they want to protect their market which sometimes seems to charge a five figure (in £'s) sum for these images...

Any help/advice would be much appreciated !

Thanks!

[John Houghton]

It's not a silly question.  You can stitch all the images together in one project.  I suggest you first of all add and align one set of images (135mm).  Then go to the Lens Settings tab and select all those images in the Individual Parameters list.  Then set the global focal length appropriate for the second set of images (70mm) and zeroise the lens paeameters a,b,c,....  Add the second set of images and create control points for the new set of images, linking them to both ends of the existing aligned images.  Optimize the second set of images with the first set unchecked.  That should give you a reasonably well aligned panorama.  You can finally try optimizing all together if necessary.  Use undo if things get worse.

John

[spoo...@gmail.com]

Thanks John !

Would you say it would be easier to first stitch the 135mm into one panorama - and then do the 70mm into a separate panorama and then stitch those two together? Rather than doing it with the individual images - the normal images I do tend to be from stadiums (with crowd) and out of 700-1000 images. So this would be maybe 600 images with 200mm and then 200-300 with 70mm.

Thanks for your advice - will need to get around to giving this a try in the near future!

[John Houghton]

On Saturday, January 11, 2014 10:06:54 AM UTC, spoo...@gmail.com wrote:

Would you say it would be easier to first stitch the 135mm into one panorama - and then do the 70mm into a separate panorama and then stitch those two together? 

In general - no.  However, given the large number of images, stitching two separate panoramas and then stitching those together would ease the processing task.  It would probably help if you could use calibrated lens parameters evaluated with full 360 degree projects. 

John

[Jim Watters]

On 2014-01-10 2:09 PM, John Houghton wrote:
> You can stitch all the images together in one project. I suggest you first of
> all add and align one set of images (135mm). Then go to the Lens Settings tab
> and select all those images in the Individual Parameters list. Then set the
> global focal length appropriate for the second set of images (70mm) and
> zeroise the lens paeameters a,b,c,.... Add the second set of images and
> create control points for the new set of images, linking them to both ends of
> the existing aligned images. Optimize the second set of images with the first
> set unchecked. That should give you a reasonably well aligned panorama. You
> can finally try optimizing all together if necessary. Use undo if things get
> worse.
>
> John
>

I've done this a few times.
I would start with the full spherical pano, with 70mm images. Then continue as
John stated, after aligning, set all these images to have individual lens
settings. You wont be optimizing FoV or distortion values for this set after
this so make sure everything is good.
Add the new higher res images, 200mm. Add control points between these images
and to the lower resolution images. You will need to manually join the two sets
of images with control points. Join the two sets where it matters. usually at
the edge of the high res images.

If merging and blending the two layers in PTGui give the higher resolution a
higher priority.
I prefer to blend the two layers together in Photoshop. So I render the low res
in its max resolution then upsample in Photoshop to match high res.

In this example I only show the higher res images as you zoom in.
http://photocreations.ca/saintjohn/?cruise_ships_4#cruise_ships_4

--
Jim Watters
http://photocreations.ca

[Erik Krause]

Am 11.01.2014 11:06, schrieb spoo...@gmail.com:
> Would you say it would be easier to first stitch the 135mm into one
> panorama - and then do the 70mm into a separate panorama and then stitch
> those two together?

I won't do this. Minor errors could accumulate from image to image
distorting the panorama such that it wouldn't align with the other. If
you have one panorama covering the whole area you can do this one first
and use it as a boilerplate for the other ones. However, I'd proceed as
John suggested since using a boilerplate has other difficulties.

--
Erik Krause
http://www.erik-krause.de

[spoo...@gmail.com]

Many thanks for all of you for the replies - will give this a try once I get a moment. Your comments are much appreciated!