360x180° Panorama Tutorial - Pt.4: Stitching in PTGui (2)

Uploaded by elfloz on 05.02.2011

Hello and welcome to Part 4 of my little panoramic photography tutorial series.
My name is Florian and I run the website Pano.ie which you're very welcome to visit.
Today I will show you how to stitch the images from the
3rd technique that I showed you in the first video of the series,
which was done with an 8mm fisheye lens on a crop camera from a tripod.
What I will show you in this tutorial is how to stitch the images together,
taking care of the tripod.
So let's open these images in PTGui Pro . . .
The first thing (because it's an 8mm fisheye lens)
is the image circle that we need to take care of. So we go to the "Crop" tab
and adjust the circle like so . . .
Just to tell PTGui which part of the image is the actual image and
which part is just the inside of the barrel of the fisheye lens.
Now, once this done, the next thing we're going to do is go to the "Advanced settings",
then go to the optimiser settings and select everything, but
now we're going to have the viewpoint corrected. This is only a feature which you find
in PTGui Pro by the way, so don't search for it if you don't have the "Pro" version.
When you look at the source images
you will see that the first six images were shot
from the same point, rotating with a panoramic head.
But the last one, this one here, was the one where I held the tripod sideways
just to get a shot of the spot where the tripod itself used to be
in the first series of images.
So, as this image is probably taken from a slightly different position,
we'll need to have the viewpoint optimisation checked in.
The viewpoint optimisation will *only* work when we have control points
from a same (common) plane. So we can't allow the control point finding algorithm to find
control points which are not on the ground of his image.
To prevent this from happening, we open the images in the "Mask" tab and
we're going to mask everything out where we don't want the control point finder
to find control points in.
So, we leave the ground in. If I hit the [Alt] key
I can remove something from the selection. Now this is all not on the ground itself
so I'm going to mask all this stuff out.
There's also a tiny bit here . . .
okay . . .
That's it.
Another thing I would do right here is just mask out the tripod itself.
When you know the [Shift] key you can draw lines, in the masking editor — which is very handy.
So let me just edit this out . . .
There we go . . .
That's that done.
I will now go align the images and let the control point finder do its job.
It will analyse the images, find the overlapping areas by finding control points and then align
them to figure out which way the images have to be arranged so that they overlap.
Now let's have a look at that. If we just run the optimiser again
we get a "Good". That's great!
Looking at the image just as it comes out of the stitching algorithm . . .
That's looking nice, and it's already pretty straight.
In that case the I will just skip adding vertical control lines. (You can see how to do this
in the last tutorial that I showed you).
When we look down it's almost perfect. There's just a wee bit off the flare left from the lens,
so switch back to the masking editor, go into the first set of images and
mask out the flare here. If you are lucky to have the 8mm fisheye lens from Sigma
(not like the Peleng I have here)
then you probably won't have these kinds of issues —
but they're very easy to take care of.
I just select the bottom here . . .
What I could also do is just copy and paste the mask.
There we go, that's a bit faster.
So let's go back to the previewer and
we will see that the ground is now flawless.
Now, the last thing I will do here is go into the "Exposre / HDR" tab
and optimise the vignetting of the lens.
I will even optimise the exposure just a wee bit,
and select the camera response curve to be the "default curve"
as we don't need this to be changed.
I'll leave the white balance untouched because I used a manual white balance,
and finally run the optimiser.
I think now that's us done with this image.
I could add some vertical control points just to straighten it up,
but depart from that we're ready to go.
So I'll go to the "Create panorama" tab — you've seen this in the previous tutorial.
I'll select some size here . . . There we go.
I'll again select the "SmartBlend" plugin,
Lanczos16 interpolator,
TIFF with LZW compression,
and finally I'll hit "Create Panorama".
So PTGui is starting its job, and
I will show you the image once the export is done.
Okay, PTGui has just finished exporting the image, so let's open it in
PanoGLView to review it . . .
I've told you about this program in the last tutorial, it's very handy to have.
There we go, let's go fullscreen
and let's have a look around . . .
That's looking really good,
we don't see any discontinuous or broken lines . . .
Now checking down in the "natural direction" or "Nadir" . . .
That also worked perfectly, you don't see any
real difference as to where
the tripod was — and that was the objective.
So there we go, as you saw it's very easy to do away with the tripod, especially with
the masking feature that was just introduced a short while ago in PTGui 9 (Pro).
So there you go, thanks for your attention in this tutorial.
I'll show you in the last part of the series
how to edit the vertical-down direction to deal with the flare issues that we had
in the first series of images.
Thanks for your attention and talk to you soon! Bye!