Stitching panoramas with large areas of featureless sky

[cvela]

I'm a relative newcomer to the world of stitching large panoramas.
I've been using PTGui for a few months, ramping up the learning
curve. A recurring challenge has been those panoramas that have areas
of featureless sky (blue sky, sky with clouds, overcast etc). Of
course in those cases no control points are generated and I'm left
with a depressing stack of blue and/or white pictures in the center of
my otherwise nice panorama. So the basic question is how to best
integrate all those lonely solo pics into the rest of the nicely
aligned and stitched panorama?

Would someone be willing to share their general workflow for such
cases? I can see many ways to approach this (and have tried a few of
my guesses) but some guidance would be appreciated. I've searched the
group for hints but if it were covered I couldn't find it (or in a way
I could understand).

thanks, -carlos

[Ken Warner]

First, you have to use a good pano head.

You don't say how many rows but lets assume you have three rows.
The nadir or bottom, a middle and a top row and the top row has
the sky.

First get the bottom and middle rows aligned properly and optimized.
Then add the top row and use Fill Yaw and don't optimize after you use
Fill Yaw. Take a look at the preview and see that all the images are
in the right place and in the right order.

Simple as that...

[cvela]

Thanks Ken. I am shooting gigapans, so for example say 12rows x
21col.
Is the idea the same? That is, get the rest of the panorama aligned
and
optimized, then manually add the y,p,r for the rest?

-carlos

[Mick Crane]

This came up recently.
If there are no discernable details then you can put in the values
manually in image parameters basing your guesses on the numbers for
images that have been successfully optimised. You can also drag
individual images around in the panorama editor. ( the blue pages icon)
Mick

[gerald.d]

Hi Carlos -

I've faced this exact problem, but found the solution remarkably
simple (different to that described by others).

Simply place your sky shots manually using the panorama editor
(dragging and dropping the images in 'roughly' the right positions).
Don't worry about control points or anything like that - just make
sure there is overlap between the images.

Here's a link to a panorama I did at the weekend that was completed in
this way -

http://dxbae.com/BD200mm.html

(full panorama is around 700MP made from 70-odd 21MP images)

Regards,

Gerald.

[Ken Warner]

You might try just aligning and optimizing the images that have
obvious features. Then adding the images that are mostly blank
and using Fill Yaw and leaving pitch and roll 0.

Fill Yaw is on the Image Parameters tab.

[cvela]

Thanks Gerald (and all) for your help. I was certainly trying to make
this harder than it is. I thought that all the images must be
connected by control points for everything to work out nicely, but I
see that once the rest of the image is aligned and straightened to
satisfaction the drag and drop method works just fine - and then let
the blender take care of any issues with clouds.

Drag and drop could get tedious for many images, but in that case I
can just type in/fill the appropriate pitch and yaw values to roughly
position the pics and then fine tune as necessary.

As a learn the ins and outs of PTGui, I am constantly aware that there
are likely better and faster ways to accomplish a given task. No
substitute for looking over someones shoulder, but I am thankful to
those who help us newcomers here.

Wonderful image Gerald ... where is that skyscraper?

-carlos

[T-Bone]

This threads a little old, but I'll try anyway.

What kind of head are you using?

[gerald.d]

Thanks for the kind comments Carlos.

The skyscraper is the Burj Dubai - the world's tallest structure.

I'm now trying another pano that should come out to around 3 to 3.5
Gigapixels, but I'm not sure my computer is up to it! (see new
thread).

Regards,

Gerald.