Luminous Landscape Forum
Raw & Post Processing, Printing => Digital Image Processing => Topic started by: nicksouth on December 23, 2010, 05:47:42 pm
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Hi all,
I was after some advice on image stitching or merging software options. The stitching or merging is required to form larger images from 3 shots taken with a shifting digital back on a technical camera. I currently use Aperture 3 software for image adjustments and processing.
Thanks in advance.
Nick.
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Hi all,
I was after some advice on image stitching or merging software options. The stitching or merging is required to form larger images from 3 shots taken with a shifting digital back on a technical camera. I currently use Aperture 3 software for image adjustments and processing.
Thanks in advance.
Nick.
I've stitched three shots from my Phase One P40+ back using Photoshop CS5 and the results are completely seamless. The process was also very efficient.
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CS5 does an outstanding job in most cases. However, it will fail in some situations such as an interior with lots of straight lines where the camera was tilted up or down with a wide angle lens. Or in some situations where certain panels are almost all monotonic such as blue sky. For the difficult situations I still use PTGui which has never failed to stitch an image, although it sometimes needs a bit of help from me in the control point editor or parametric settings.
CS5's greatest weakness is that the user can not intervene directly to correct bad stitches. It's second greatest weakness is that it does not have the Verdutismo projection which is useful in architecture.
In any case CS5 has the best blending algorithm available today, and I usually output stitched, layered files from PTGui to be blended in CS5.
CS5 can not correctly stitch this (http://www.unit16.net/Adobe%20Web%20Gallery/content/bin/images/large/Tondreau_Albuquerque_Railyard.jpg) image...yet.
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I believe that Autopano Giga 2.5 (currently in RC status) and PTgui Pro 9.0 are the kings of the hill.
They scale really well to gigapixels panos, are both very automated (APG more so) and very fast. They offer very advanced manual control when required in dedicated interfaces that have been designed for the job. They are also connected to a very large and deep community of pano experts that are driving the software in the right direction.
Cheers,
Bernard
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I believe that Autopano Giga 2.5 (currently in RC status) and PTgui Pro 9.0 are the kings of the hill.
They scale really well to gigapixels panos, are both very automated (APG more so) and very fast. They offer very advanced manual control when required in dedicated interfaces that have been designed for the job. They are also connected to a very large and deep community of pano experts that are driving the software in the right direction.
Cheers,
Bernard
Now Bernard, we just learned the other day that all that talk about PTgui over the years was just a camouflage for your really preferred application. Sorry, you've blown your cover - can't go back. :-)
But seriously yes - it is a very sophisticated tool which has obviously gotten better and easier to use over the years; however a nice thing about using Photoshop (apart from the fact that stitching is included in the price) is the immediate integration with other cool tools that can come in handy when doing panos - such as Content Aware Fill. Of course one can use those too after porting a PTgui job into Photoshop.
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Now Bernard, we just learned the other day that all that talk about PTgui over the years was just a camouflage for your really preferred application. Sorry, you've blown your cover - can't go back. :-)
:)
But seriously yes - it is a very sophisticated tool which has obviously gotten better and easier to use over the years; however a nice thing about using Photoshop (apart from the fact that stitching is included in the price) is the immediate integration with other cool tools that can come in handy when doing panos - such as Content Aware Fill. Of course one can use those too after porting a PTgui job into Photoshop.
Stitching capability in PS has for sure reached an excellent level with CS5. I tend to use it when dealing with DoF stacked images whose crop is not always consistent between frames, which can generate issues with either of the recommendation above.
Just like cameras/formats... they are just tools in the end. ;D I see no reason not to use my expensive CS5 license to the best of its abilities but I still hesitate to recommend it for people starting pano work. I feel it is a good tool to have among others and why not try its pano capability if you own a CS5 license, I just wouldn't want folks to think that all the things CS5 cannot do define the envelope for stitching.
Cheers,
Bernard
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For "flat" stitching based on shifted captures off a tech camera Photoshop's merger is fine.
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For "flat" stitching based on shifted captures off a tech camera Photoshop's merger is fine.
Yes, I agree. With a fixed lens entrance pupil and a sensor shifted around the image circle, stitching is not more difficult than plain translation in a flat plane. It can even be done manually very easily, just increase the canvas size in Photoshop, and shift the layers (temporarily using difference blending makes alignment easy) into registation. Then mask at the overlap, e.g. with a gradient. Just make sure the exposures are constant.
Cheers,
Bart
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Yes, I agree. With a fixed lens entrance pupil and a sensor shifted around the image circle, stitching is not more difficult than plain translation in a flat plane. It can even be done manually very easily, just increase the canvas size in Photoshop, and shift the layers (temporarily using difference blending makes alignment easy) into registation. Then mask at the overlap, e.g. with a gradient. Just make sure the exposures are constant.
in theory, yes. This would require a sensor that is absolutely not tilted/swinged/rotated (at least less than 6.8 microns on the said P45) and at the same time a camera with a perpendicular alignement on every axis within the tolerances of the sensor's pixel pitch. The camera would have to hold these tolerances also at large movements. I don't think that such a camera exists. Too, it would require a tripod and tripod head that moves less than the sensor's pixel pitch when you operate the camera (i.e. when you adjust the shift for the stitching).
Finally it would also require a motif without any movement (clouds, trees... whatever).
That said I have infact been stitching some images manually and it wasn't really a problem.
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................ I just wouldn't want folks to think that all the things CS5 cannot do define the envelope for stitching.
Cheers,
Bernard
Good point.
Mark
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in theory, yes. This would require a sensor that is absolutely not tilted/swinged/rotated (at least less than 6.8 microns on the said P45) and at the same time a camera with a perpendicular alignement on every axis within the tolerances of the sensor's pixel pitch. The camera would have to hold these tolerances also at large movements. I don't think that such a camera exists.
That's correct, but in practice the differences are small, and registration to less than 1 pixel difference is feasible. A misalignment by a fraction of a pixel will be very hard to detect. Sensor rotation requires translation in 2 directions to eliminate most of it. By doing a manual transition mask in the overlap area, the residual error becomes even smaller.
Too, it would require a tripod and tripod head that moves less than the sensor's pixel pitch when you operate the camera (i.e. when you adjust the shift for the stitching).
Good technique is assumed, but you are correct in mentioning it.
Finally it would also require a motif without any movement (clouds, trees... whatever).
Obviously, that applies to all approaches that require multple exposures.
That said I have infact been stitching some images manually and it wasn't really a problem.
Indeed, my experience as well. When the overlap between image tiles is large enough then a lot can be covered up, including some subject motion.
Cheers,
Bart
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Finally it would also require a motif without any movement (clouds, trees... whatever).
Obviously, that applies to all approaches that require multple exposures.
yes, of course!
When the overlap between image tiles is large enough then a lot can be covered up, including some subject motion.
the cool thing with flat stitching within a larger image circle is you basically only need very little overlapping. You actually only need it to cover subject motion.
When stitching in Photoshop I always use the "recomposition" mode (so not the "auto" mode). In this mode no interpolation (rotation, scaling, squeezing) is introduced... so all Photoshop has to do is to find the stitching seam. Mostly Photoshop is really good in that. If there are some errors in the stitching seam you can still repair those errors with retouching on the layers easily.
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Hi,
Smart Blend available in Autopano Pro and other programs is really good about handling things that move, they are actually quite magic. That said they are not perfect.
I use sometimes Photoshop CS5 because it has workflow advantages but I'd say that Autopano Pro gives better results on anything slightly problematic.
I have a couple of write-ups on panos:
http://echophoto.dnsalias.net/ekr/index.php/photoarticles/panorama-and-stitching
Some good comments on that article: http://www.luminous-landscape.com/forum/index.php?topic=36973
http://echophoto.dnsalias.net/ekr/index.php/photoarticles/21-panoramas-quick-a-dirty
Best regards
Erik
Obviously, that applies to all approaches that require multple exposures.yes, of course!
the cool thing with flat stitching within a larger image circle is you basically only need very little overlapping. You actually only need it to cover subject motion.
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Smart Blend available in Autopano Pro and other programs is really good about handling things that move, they are actually quite magic. That said they are not perfect.
True enough, but I really like Autopano's 'Anti-Ghost' feature... MOST of the time...
"Photographing Moving Water (http://www.wolfnowl.com/2010/12/photographing-moving-water/)"
Mike.
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True enough, but I really like Autopano's 'Anti-Ghost' feature... MOST of the time...
"Photographing Moving Water (http://www.wolfnowl.com/2010/12/photographing-moving-water/)"
Mike.
Very interesting article Mike, thks for sharing!
Cheers,
Bernard
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Very interesting article Mike, thks for sharing!
Cheers,
Bernard
ditto - and fine photography.
I'm thinking of biting the bullet and buying the neutral density filters, much as I see that with determined and good post-capture procedure you can come close to the appropriate effects without them.