Tutorial video on stereo stitching

[Tom Sharpless]

I've just published the first of what I hope will be several tutorials on the method I have developed  for stitching stereoscopic panoramas with PTGui 12.  I  call it multi-patch warp-to-fit.  In contrast to my previous efforts, it  always seems to work, and can be applied systematically, even mechanically in many cases.

This video is about one such case, an outdoor scene that I had been unable to stitch in several previous tries, but that stitched beautifully with multi-patch 'on autopilot', in a total working time of 18 minutes 43 seconds.

Your comments and criticisms will be welcome.

https://www.youtube.com/watch?v=t5jfxSbd0cI

[Jim Watters]

Tom,

Fantastic work. Great stitch and simplification of the process.

Why did you choose the log to join the two groups? I would think you would use something closer to the tripod. Why not add a point to the zenith?

It may not be obvious to some that by having the global lens profile set to optimize FoV, a, b, c, Shift long, and Shift short when you add the other lens profiles these parameters will be copied to the new lens. After optimization each lens will have it's own slightly different values for these settings.

You called it Warp to fit. But it is something slightly different. Warp to fit or viewpoint correction is not what is being done here. This is something much more controlled. It is allowing each set of images to have a similar constrained distortion to align them up correctly.

Will this work with only one row? Does it need the multiple rows to allow the right distortion to align things?

Joost,

I am wondering if it is possible to tag images. then we can select them by their tag.

For stereo could tag the images either Left or Right. And for Tom's multi row tag them top and bottom too.
I would use it in my star panos to tag the star and foreground images.

Maybe context menu to pop up a list of tags to choose from. Anywhere you have a Select All could have a select by tag.

Not sure if selecting a second one should add to the selection or use Ctrl as a modifier to add to the selection. Using Ctrl might be too hidden. So two menus one to add and one to remove lens profiles. This would only be visible if there are tags.

Jim Watters

--
You received this message because you are subscribed to the Google Groups "PTGui Support" group.
To unsubscribe from this group and stop receiving emails from it, send an email to ptgui+un...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/ptgui/6265a887-6cf5-4f3d-bb90-67f36d18f285n%40googlegroups.com.

[Jürgen Schrader]

Yes! I second to add tagging :-)

Jürgen Schrader

BAVARIA360.DE

+49-151-40036755

jsch...@bavaria360.de

Am 24.02.2021 um 05:59 schrieb Jim Watters <jwat...@photocreations.ca>:



To view this discussion on the web visit https://groups.google.com/d/msgid/ptgui/58b955b0-8625-02cb-dec8-29f6676b38cb%40photocreations.ca.

[PTGui Support]

Great work Tom, I'm impressed!
I was surprised to see you're not using viewpoint correction and still
get a good stitch.

Jim, you're right, I can see tagging would be very useful here. It was
on the wish list already,

Kind regards,

Joost Nieuwenhuijse
www.ptgui.com

>> <mailto:ptgui+un...@googlegroups.com>.

>> To view this discussion on the web visit
>> https://groups.google.com/d/msgid/ptgui/6265a887-6cf5-4f3d-bb90-67f36d18f285n%40googlegroups.com

>> <https://groups.google.com/d/msgid/ptgui/6265a887-6cf5-4f3d-bb90-67f36d18f285n%40googlegroups.com?utm_medium=email&utm_source=footer>.

>
> --
> You received this message because you are subscribed to the Google
> Groups "PTGui Support" group.
> To unsubscribe from this group and stop receiving emails from it, send
> an email to ptgui+un...@googlegroups.com

> <mailto:ptgui+un...@googlegroups.com>.

> To view this discussion on the web visit

> https://groups.google.com/d/msgid/ptgui/58b955b0-8625-02cb-dec8-29f6676b38cb%40photocreations.ca
> <https://groups.google.com/d/msgid/ptgui/58b955b0-8625-02cb-dec8-29f6676b38cb%40photocreations.ca?utm_medium=email&utm_source=footer>.

[Tom Sharpless]

Thanks, guys.

I too am surprised how well this works with just a lens profile per row.   I guess that is because the  required warp is pretty systematic -- the near foreground needs to be pulled together at nadir while remaining spread out at middle distance, and a vertical lens shift can do that.  I do add viewpoint correction selectively when needed, for example to flatten large floor areas, which have a slightly domed shape in 3D with only a custom lens profile.  I have not found it helpful to use lots of individual lens parameters -- even though PTGui's optimizer is fantastically well stabilized, one can't expect good results when the problem is very much underdetermined.  

The multi-patch method works fine with one row of photos -- provided you divide them into two rows of patches (3 in case of a detailed low ceiling)!  An upcoming video will show a stereo stitch from a single row of 6 views split into 12 patches.

Of course I vote for tags too.  It should be possible to select all images of a tag set..

  --  for masking and CP generation, as if selected in sources tab

  -- for display and stitching, as if selected in create pano tab

  -- for optimization (or not) as if selected in optimizer tab