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Author Topic: Problem stitching  (Read 6440 times)

bellimages

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Problem stitching
« on: August 08, 2010, 05:29:07 pm »

I shot a series of shots, intending to stitch them together. They were shot with a 70-200 lens, set at 70mm, I used a tripod .... pano head .... the whole nine yards. When Photoshop stitched them, the end result was an arched image (see attachment). Can I get Photoshop to correct this? Or is there software that would do the stitch without the arch?
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Luis Argerich

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Problem stitching
« Reply #1 on: August 08, 2010, 05:59:57 pm »

IMHO Photoshop is quite bad at stitching, specially at placing control points.
Try with PtAssembler, Hugin or PtGUI, those are much much better for the task.
If the clouds moved fast and you didn't have enough overlap between shots it may be a problematic stitch.

bellimages

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Problem stitching
« Reply #2 on: August 08, 2010, 06:11:02 pm »

Quote from: Luis Argerich
IMHO Photoshop is quite bad at stitching, specially at placing control points.
Try with PtAssembler, Hugin or PtGUI, those are much much better for the task.
If the clouds moved fast and you didn't have enough overlap between shots it may be a problematic stitch.
As you can see, that doesn't seem to be the problem. It's just that Photoshop wants to put in that huge arch. I could see this problem might arise had I used a wide angle lens. But it was shot at 70mm
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NikoJorj

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Problem stitching
« Reply #3 on: August 08, 2010, 06:34:31 pm »

Quote from: bellimages
Or is there software that would do the stitch without the arch?
Any decent pano stitcher will allow you to specify an horizon to avoid this... Try Hugin eg, it's free.

Correction the shot afterwards in PS could be done with the Warp command, but it wouldn't be easy to do it really right.
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Schewe

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Problem stitching
« Reply #4 on: August 08, 2010, 08:47:03 pm »

Quote from: bellimages
When Photoshop stitched them, the end result was an arched image (see attachment).


Did you use the Auto setting? I find the Cylindrical options often does a better job of stitching than the Auto option. And yes, you can fix the arch with warp...pretty easy actually..draw out a guide for the center area where you want to warp the outer edges that tilt up. If you turn the payers into a Smart Object, you can apply the warp after the SO conversion while keeping the layers intact in the SO.
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Lisa Nikodym

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Problem stitching
« Reply #5 on: August 08, 2010, 09:23:26 pm »

In my experience, I get arched stitches like that only when I wasn't careful to level the tripod and camera.  Could that be the cause in this case???

Lisa
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BernardLanguillier

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Problem stitching
« Reply #6 on: August 09, 2010, 12:53:10 am »

Quote from: bellimages
I shot a series of shots, intending to stitch them together. They were shot with a 70-200 lens, set at 70mm, I used a tripod .... pano head .... the whole nine yards. When Photoshop stitched them, the end result was an arched image (see attachment). Can I get Photoshop to correct this? Or is there software that would do the stitch without the arch?

As a faithful Adobe customer, I know that PS does many things right, but overall their pano engine is behind the curve.

PTgui and Autopano pro have a very significant lead.

Cheers,
Bernard

bellimages

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Problem stitching
« Reply #7 on: August 09, 2010, 11:20:52 am »

Okay, let me ask this .....

I've gone to great expense to travel to some locations. I've spent mega bucks on gear. Now, it's time to assemble some panorama images. The software ranges in price from $203 (PTgui) to $29 for PTAssempler and free Hugin.

I've always felt that you get what you pay for. My concern with the free, or cheap, software is that it could degrade the quality of my frames. Granted, it might stitch them together fine, but will it preserve the quality ..... which is critical to producing a gallery image.
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JohnBrew

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Problem stitching
« Reply #8 on: August 09, 2010, 11:29:46 am »

You don't specify which PS you are using. I find CS4 does an excellent job. (for me   )

bellimages

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Problem stitching
« Reply #9 on: August 09, 2010, 11:56:47 am »

I just tried Schewe's suggestion of the Cylindrical Option in PS. It worked very well.

So tell me, why should I consider the $250 option? Trust me ..... I can be convinced, but I just need to know why I'd spend that much on software that will do the same thing as Photoshop.
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Wim van Velzen

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Problem stitching
« Reply #10 on: August 09, 2010, 01:29:11 pm »

You could also try the 'reposition' option within the Photoshop photomerge tool.

Stitching is a bit of hit and miss with PS indeed - and it seems it is not always the difficult situations that go wrong!
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Bart_van_der_Wolf

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Problem stitching
« Reply #11 on: August 09, 2010, 01:49:55 pm »

Quote from: bellimages
I just tried Schewe's suggestion of the Cylindrical Option in PS. It worked very well.

So tell me, why should I consider the $250 option? Trust me ..... I can be convinced, but I just need to know why I'd spend that much on software that will do the same thing as Photoshop.

Cylindrical is just one of many possible projection methods. It's main characteristics are that verticals will remain straight verticals, any horizontal features other than the horizon will be curved, it is possibler to span huge angles of view.

The part that's troublesome, from a realism point of view, is the curved horizontals. If you don't care about how the software distorts the image, by all means stick to Photoshop. Dedicated software offers more choices, the user is incharge, not the software.

Cheers,
Bart
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feppe

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Problem stitching
« Reply #12 on: August 09, 2010, 02:02:58 pm »

Quote from: bellimages
Okay, let me ask this .....

I've gone to great expense to travel to some locations. I've spent mega bucks on gear. Now, it's time to assemble some panorama images. The software ranges in price from $203 (PTgui) to $29 for PTAssempler and free Hugin.

I've always felt that you get what you pay for. My concern with the free, or cheap, software is that it could degrade the quality of my frames. Granted, it might stitch them together fine, but will it preserve the quality ..... which is critical to producing a gallery image.

Some of the programs have demos you can test for yourself. I've tested out both PTGUI and Autopano Pro, and have found they both do a good job, and complement each other where the other one fails. APP isn't nearly as good for bracketed panos, but PTGUI has a poorer UI and tends to fail on tough stitch jobs more often. I don't bother trying with manual control point creation so YMMV.

Dick Roadnight

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Problem stitching
« Reply #13 on: August 09, 2010, 02:17:56 pm »

Quote from: bellimages
So tell me, why should I consider the $250 option? Trust me ..... I can be convinced, but I just need to know why I'd spend that much on software that will do the same thing as Photoshop.
It would be nice to think that Photoshop, at £2,500 with all the bells and whistles, would do everything you ever wanted it to do,,, but it will not.

If you have spent "megabucks" on kit, $250 is insignificant... if you want to do pano, it will be worth finding out how to use it. The question is, Bernard, is it worth getting PT-Gui and Autopano pro? is each the best in different situations?

Try panning something simple with a straight horizon (or some guide line through all the frames, even a curved power line). The movement (rotation) of the clouds may have made the software think that the tripod and camera were not level.
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Dick Roadnight

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Problem stitching
« Reply #14 on: August 09, 2010, 02:22:37 pm »

sorry, double post
« Last Edit: August 09, 2010, 02:23:41 pm by Dick Roadnight »
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BernardLanguillier

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Problem stitching
« Reply #15 on: August 09, 2010, 06:39:19 pm »

Quote from: Dick Roadnight
The question is, Bernard, is it worth getting PT-Gui and Autopano pro? is each the best in different situations?

Dick,

I would say if you only get one and don't care too much for manual optimization, get autopano pro.

If you need to handle a wide set of situations and look for the best possible output, then get both.

Going more into the details:

- If you are mostly into urban panos, get PTgui,
- If you do mostly nature panos with lots of skies, then get Autopano pro

Cheers,
Bernard

Dick Roadnight

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Problem stitching
« Reply #16 on: August 10, 2010, 02:40:00 am »

Quote from: BernardLanguillier
Dick,

I would say if you only get one and don't care too much for manual optimization, get autopano pro.

If you need to handle a wide set of situations and look for the best possible output, then get both.

Going more into the details:

- If you are mostly into urban panos, get PTgui,
- If you do mostly nature panos with lots of skies, then get Autopano pro

Cheers,
Bernard
Thank you very much, Bernard...

I will be doing manual optimization, landscape and villages (initially harbours) so I think I will need both.
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Bart_van_der_Wolf

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Problem stitching
« Reply #17 on: August 10, 2010, 03:34:09 am »

Quote from: Dick Roadnight
I will be doing manual optimization, landscape and villages (initially harbours) so I think I will need both.

Hi Dick,

If you are working on a Windows OS platform, I'd suggest to have a look at PTAssembler. It's not just its low price, but it is a real workhorse for problematic situations. It also offers a huge choice of adjustable projection methods. The user interface is not as sleek as some of the other contenders, but its capabilities are second to none. When you're on a Mac platform, I guess PTGUI is quite close in manual intervention capabilities, when (not if) things go wrong on automatic control (as they will sooner or later).

The current (stable) beta version of PTAssembler (available through the PTAssembler forum pages) has a choice of interpolation algorithms including Sinc1024 which can keep the image very sharp despite the image warping needed to make the images align. It also has special masking possibilities, e.g. to mask overlapping objects in one or both of the images, and it has a sofar unique camera position optimizer for flat plane stitches from images taken from different positions/angles.

I always use PTAssembler when Autopano Giga makes a mess of the images (again). There is a new version of Autopano on the horizon which supposedly addresses some of its shortcomings by offering less 'auto' and more control for those problem cases, but I'll have to see it working before I believe it.

Cheers,
Bart
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Dick Roadnight

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Problem stitching
« Reply #18 on: August 10, 2010, 04:50:11 am »

Quote from: BartvanderWolf
Hi Dick,

If you are working on a Windows OS platform, I'd suggest to have a look at PTAssembler. It's not just its low price, but it is a real workhorse for problematic situations. It also offers a huge choice of adjustable projection methods. The user interface is not as sleek as some of the other contenders, but its capabilities are second to none. When you're on a Mac platform, I guess PTGUI is quite close in manual intervention capabilities, when (not if) things go wrong on automatic control (as they will sooner or later).

The current (stable) beta version of PTAssembler (available through the PTAssembler forum pages) has a choice of interpolation algorithms including Sinc1024 which can keep the image very sharp despite the image warping needed to make the images align. It also has special masking possibilities, e.g. to mask overlapping objects in one or both of the images, and it has a sofar unique camera position optimizer for flat plane stitches from images taken from different positions/angles.

I always use PTAssembler when Autopano Giga makes a mess of the images (again). There is a new version of Autopano on the horizon which supposedly addresses some of its shortcomings by offering less 'auto' and more control for those problem cases, but I'll have to see it working before I believe it.

Cheers,
Bart
Thanks, bart...

I only use Mac computers at the moment

When I was in Padstow Harbour the other day I was thinking it was the ideal situation for cylinder pano... a semi-circularish row of old stone buildings round the harbour...

But I would have to eliminate the masts and rigging of boats in the foreground... taking alternative shots from different positions (with a 10m Manfrotto Agnoskope) to mask out the unwanted foreground rigging... is there a quick and easy way to do this?

This is not "flat plane stitching"... ¿but I could do flat plane stitches of individual buildings and then cylinder stitch from those pix?

That day I spoke to gallery owners, and one (not in Padstow itself) said that photographs were "just what was in front of the photographer when they push the button"
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BernardLanguillier

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Problem stitching
« Reply #19 on: August 10, 2010, 05:06:07 am »

Quote from: Dick Roadnight
This is not "flat plane stitching"... ¿but I could do flat plane stitches of individual buildings and then cylinder stitch from those pix?

Yes, you could of course do that, but in the end the cylindrical projection will end up getting rid of straight horizontal lines anyway.

It it worth trying, but I am not sure you will get significantly better image quality compared to "native" cylindrical stitching. I am afraid you will just waste time with the left/right shifts of the camera at each position of the cylinder.

Besides, the taller the image the better for cylindrical projection.

As far as getting rid of the foregound, is there no way to get to a higher location?

- building
- rental crane
- helicopter

Regards,
Bernard
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