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Thread: A technique for stitching hand held panoramas

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John Houghton

Posts: 3935
Location: Hitchin, United Kingdom
Registered: 17 Jan 2005
A technique for stitching hand held panoramas
Posted: 13 Mar 2014 at 11:10 GMT
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Last summer I shot some panoramas in Peterborough with a hand held 5DII + 12mm fisheye and had awful problems dealing with the inevitable alignment errors in paved surfaces. I recently thought of a better way to tackle these and having tried it on two sample panoramas, I can report that it gives astonishingly good results with relative ease. The method may well not be entirely original, but I thought I would share it with you as it may come in handy when use of a tripod is impractical or prohibited for any reason.

In brief, I srarted a PTGui project with the 6 shots around + zenith, and then added the same 6 images into the PTGui project a second time. The idea behind this was to use the duplicate images as offset nadir shots of the floor - to be aligned with viewpoint correction. So the top half of the panorama was treated as per normal, with control points only on the distant features in the first set of 6 images. The bottom half (largely the ground) was to be stitched from the second set. The images in the second set were aligned using many control points between each other and just two or three points to align each with the most distant floor features near the horizon in the first set (where there is minimal parallax). The result straight out of PTGui was amazingly good as far as the floor was concerned, with no visible glitches at all except for a few minor errors in the far distance where the two sets of images meet. Masking was used of course to select which parts of each set made it into the final panorama.

Naturally, this didn't help at all with the alignment problems of near objects like furniture and (moving) people. These still had to be dealt with with the usual ways. But the integrity of the paved areas was assured and saved a lot of painstaking work to make it so.

Here are the results from my two test projects, generated from the ev0 images of the bracketed sets. View them simply as evidence of the good quality stitching of the floor obtained. No separate nadir shot was used in the first. A separate nadir shot was used in the second one just to remove my shadow.

www.johnhpanos.com/test/petbo2/petbo2.html
www.johnhpanos.com/test/petbo3/petbo3.html

John
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burake

Posts: 336
Location: Antalya, Turkey
Registered: 7 Jun 2012
Re: A technique for stitching hand held panoramas
Posted: 4 Apr 2014 at 20:16 GMT
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Great results for a set of handheld shot images. Thank you for your sharing John..
Burak
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DennisS

Posts: 1787
Location: Los Anglels, United States
Registered: 1 Sep 2007
Re: A technique for stitching hand held panoramas
Posted: 5 Apr 2014 at 3:49 GMT
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Another way to improve your hand held skills is to shoot with a monopod. You develope muscle memory and can hold the camera so close to the NPP.

Thanks for the info John. I use it with my monopod panos as sometimes the nadir patch just does not work. One stich for the upper half (PTGui blender), one stitch for the lower half (Smartblend), combine and mask in Photoshop.
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aaronho

Posts: 7
Location:
Registered: 8 Apr 2014
Re: A technique for stitching hand held panoramas
Posted: 8 Apr 2014 at 12:33 GMT
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I agree with Burake as the photographs are incredible considering you captured them with a hand help camera! Great work!

Corporate Photography Sydney
voozzi.bcz.com/2014/03/19/corporatephotography/
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Nick Fan
[NodalNinja]

Posts: 770
Location: Hong Kong
Registered: 26 May 2006
Re: A technique for stitching hand held panoramas
Posted: 11 Apr 2014 at 17:56 GMT
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John,

Great tip. Thx for sharing. I guess this technique can be used to fix parallax issue in general. Fix parallax here using a set of images, Fix parallax there using another set. blend them. Bingo.

Nick
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BwanaQ

Posts: 21
Location:
Registered: 24 Aug 2012
Re: A technique for stitching hand held panoramas
Posted: 11 Apr 2014 at 21:07 GMT
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Thank you for sharing your techniques John. You make Peterborough look inviting.
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cartola

Posts: 1
Location: Rio de Janeiro, Brazil
Registered: 22 Apr 2014
Re: A technique for stitching hand held panoramas
Posted: 22 Apr 2014 at 15:01 GMT
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Thank you for the sharing John!

Have you tried to make only one extra picture of the floor to stitch it with viewpoint correction? It looks simpler, but don't know if it would have the same good result. I've already done that when using tripod and stitched in Hugin.

Here is what I've done:

cartola.org/panoforum/viewtopic.php?f=19&t=32

The post is in Portuguese but I guess the pictures can illustrate. I think the viewpoint correction was made to be used like this, just mentioning here to be sure that you've tried and got better results the way you did.

Bests.
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John Houghton

Posts: 3935
Location: Hitchin, United Kingdom
Registered: 17 Jan 2005
Re: A technique for stitching hand held panoramas
Posted: 22 Apr 2014 at 15:07 GMT
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Yes, I normally use a single viewpoint nadir in the conventional way when shooting with a tripod. It's only when shooting handheld that you can run into problems with a nadir shot not aligning properly with all the horizontal row of shots.

John
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DennisS

Posts: 1787
Location: Los Anglels, United States
Registered: 1 Sep 2007
Re: A technique for stitching hand held panoramas
Posted: 22 Apr 2014 at 18:26 GMT
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Sitting here working on my monopod panos from last week I was reminded of another option to help panos stitch.

If I find that PTGui just is not able to warp a section of an image, I manually warp the image in Photoshop prior to stitching. It is so very easy to do. You have both Photoshop and PTGui open at the same time. You nudge the section of the image that will not line up, save and review the results almost instantly in PTGui. Many a pano has been saved this way.

I have also brought in the same hand held Nadir image multiple times, masking out the problem areas. There is nothing in PTGui that keeps you from adding the same image multiple times.
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paintballbudd

Posts: 9
Location: United States
Registered: 5 Mar 2014
Re: A technique for stitching hand held panoramas
Posted: 29 Jun 2014 at 8:19 GMT
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dl.dropboxusercontent.com/u/94446900/colorado1b_o...

created 4 years ago from handheld canon s90 using autopano
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