Best way to grab a screen shot of an equirectangular panorama?

[aaronpriest]

What is the best method of manipulating a spherical (equirectangular) panorama and saving out some still shots? I've seen a couple plugins for Photoshop, but the ones I tried didn't work very intuitively. Right now I'm loading them into PTGui with lens type set to equirectangular panorama, 360° field of view, projection set to rectilinear (flat), with a field of view around 120°. I can rotate the image about numerical transform tool and save very high resolution screen shots that way. However the depth perception is quite over-exaggerated. For example, in this screenshot, the shower is actually not square--it is wider than it is deep. Any other projection bows and curves lines badly. Any ideas?

[Erik Krause]

Am 08.04.2013 15:04, schrieb aaronpriest:
> For example, in this screenshot, the
> shower is actually not square--it is wider than it is deep. Any other
> projection bows and curves lines badly. Any ideas?

What you see is a geometrically correct perspective. You only choose a
too wide angle of view. Any other tool that extracts rectilinear views
from equirectangular will deliver the same result.

And no, there is no projection that preserves all straight lines. The
best approximation is probably one of the vedutismo projections.
Experiment with the Projection settings in the bottom left corner of
panorama editor.

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

[aaronpriest]

I guess what confuses me is that I shot the full sphere from that spot with my 14mm lens in portrait orientation. If I had taken a separate shot in landscape orientation I would have got the cropped photo I wanted (minus the ceiling and floor) without that extra exaggerated depth. Choosing a narrower angle of view does not give me the coverage my 14mm would have given (more like 35mm to 50mm). Why is this? Then again, maybe I would have stepped back a bit to fit all that in my 14mm shot and I'm overestimating it in my mind when I attempt to crop it out of the scene?

[John Houghton]

On Monday, April 8, 2013 4:44:32 PM UTC+1, aaronpriest wrote:

If I had taken a separate shot in landscape orientation I would have got the cropped photo I wanted (minus the ceiling and floor) without that extra exaggerated depth.

Alas, you are wrong.  The result from taking a separate shot would be identical to a view extracted from the panorama. The "distortion" is a perspective characteristic that is particular to the viewpoint from which the shots are taken.

John

[aaronpriest]

I did mention that I could be overestimating the distance in my mind. :-)

So, is there a way of compressing the "exaggerated" depth in Photoshop? 

Is there a good plugin for Photoshop for manipulating equirectangular images without going through the PTGui route I'm doing now? It's works OK, but it's not overly intuitive from a creative/artistic point of view. I'd rather rotate things around freehand and zoom in/out to see what I like than punch numbers into a tool and export. :-)

[John Houghton]

On Monday, April 8, 2013 5:22:10 PM UTC+1, aaronpriest wrote:

 I'd rather rotate things around freehand and zoom in/out to see what I like than punch numbers into a tool and export. :-)

Well, you can do all that in PTGui just by dragging the image in the Panorama Editor window (+ ctrl to rotate) and zoom in/out via the two scroll bars.  Further, you can drag in yellow crop bars from the edges of the panorama image frame.

John

[Erik Krause]

Am 08.04.2013 18:22, schrieb aaronpriest:

> Is there a good plugin for Photoshop for manipulating equirectangular
> images without going through the PTGui route I'm doing now? It's works OK,
> but it's not overly intuitive from a creative/artistic point of view. I'd
> rather rotate things around freehand and zoom in/out to see what I like
> than punch numbers into a tool and export.

You might want to try flexify (by Flaming Pear), which does a gazillion
of different remapppings, but I fear it's even less intuitive when it
comes to rectilinear.

But there is DevaVR standalone where you can pan around and save any
view: http://www.devalvr.com/paginas/productos/index.html

For special projections you might want to try panini perspective tool:
http://pvqt.sourceforge.net/

[John Houghton]

On Monday, April 8, 2013 5:30:17 PM UTC+1, John Houghton wrote:

Well, you can do all that in PTGui just by dragging the image in the Panorama Editor window (+ ctrl to rotate)

Actually, it's  drag with right mouse button to rotate the panoramna.  Sorry about the slip..

John

[Chris Erskine]

why don't you set your panaroma up to output a Vedutismo projection instead of a rectilinear or equirectangular.

you can have your wide angle shot and then compress it so you get less distortion.

arh just seen someone mentioned panini. which is the same thing.

chris

John

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[DennisS]

Not too sure if this applies.  On my Windows computer the way I take screen shots is while viewing a completed panorama I hit alt + Print Screen, open Photoshop (or mspaint) and paste in the screen capture.  Not sure if this is what the original question was asking about.  Works for any panorama, even those published on the Internet.