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Author Topic: not align phots  (Read 8698 times)

Chiara

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not align phots
« on: July 16, 2013, 01:35:30 PM »
Agisoft does't align us every kind oh photos.  :o
The procedure is correct, I follow the user manual and tutorials, maybe I need some special precautions for the settings of the camera.
Could you help me, please?
Thank you in advance.
Chiara

aphextwin

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Re: not align phots
« Reply #1 on: July 16, 2013, 01:37:17 PM »
Can you provide your images?

Chiara

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Re: not align phots
« Reply #2 on: July 16, 2013, 02:01:43 PM »

aphextwin

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Re: not align phots
« Reply #3 on: July 16, 2013, 02:10:32 PM »
There are some issues that you need to refine:
- The object needs to be focused on every image (which is not the case on most images)
- try to hold the brightness on the object on every image
- try to get "most of the image" on the sensor (get closer to the object, not get parts of the object, better the whole object)

cheers

Alexey Pasumansky

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Re: not align phots
« Reply #4 on: July 16, 2013, 03:20:09 PM »
Hello Chiara,

I totally agree with aphextwin recommendations.
Also I recommend to turn off image auto-rotate feature on your camera.

Maybe capturing scenario should be also revised.

However, on this dataset I've managed to get some result by adding masks (but it will be much better if you can reshoot the object according to the recommendations):
Best regards,
Alexey Pasumansky,
Agisoft LLC

Chiara

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Re: not align phots
« Reply #5 on: July 16, 2013, 07:07:15 PM »
Thank you both for your response. You are perfectly right about all the observations made on the photos, but it was only a test to start.
Thanks especially for the photo-processing, in fact by comparison, though using the same material the results are different.

In the first image, for example, there are two giraffes.
In particular, the alignment of the camera, which I have in random position. (second image)
The geometrical model is even worse. (third image)

Surely I do something wrong, but I do not know what!
Maybe is something related to the fact that I have a trial version?

Could you explain your steps to get that model?

Thanks for your patience.

Chiara

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Re: not align phots
« Reply #6 on: July 16, 2013, 07:09:23 PM »
screenshots

Alexey Pasumansky

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Re: not align phots
« Reply #7 on: July 16, 2013, 07:25:37 PM »
Hello Chiara,

These problems with the photo alignment (that results in the effects you are observing) are caused by poor quality of original images.
So even for test purposes I recommend you to re-shoot the object to get things working properly. If there is an option to take better images for problematic dataset, it is always better than working with the bad data, that's my opinion.

But anyway, here is my workflow for current dataset:
- apply masks to the photos, leaving only the object of interest,
- align photos (High, no pre-selection, constrain features by mask - on),
- adjust bounding box,
- build geometry (Arbitrary, smooth, medium, face count - 300 000).
Best regards,
Alexey Pasumansky,
Agisoft LLC

Chiara

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Re: not align phots
« Reply #8 on: July 16, 2013, 07:44:26 PM »
Thanks, I'll try to do the same settings.
Maybe it will be good as yours. I will let you know tomorrow.

Cheers
Chiara

sea313

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Re: not align phots
« Reply #9 on: July 18, 2013, 05:26:46 PM »
Hi,
I have the same problem!
I have followed your suggestions but nothing happens!
Why?What's wrong?
I need to get results as soon as possible.  :'(
could you post a tutorial, step by step, with chiara's pictures, please? :)
Thank you in advance.
Serena

Chiara

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Re: not align phots
« Reply #10 on: July 18, 2013, 09:40:44 PM »
I solved the problem simply delating not focused photos. Only 22 photos gave me a decent model.
The only input of the program are the photos, so it is crucial that they are good, it's the advice I can give as a beginner.  ;)

Cheers

Alexey Pasumansky

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Re: not align phots
« Reply #11 on: July 18, 2013, 09:49:54 PM »
Hello Serena,

Could you please share photos you are trying to process?
Best regards,
Alexey Pasumansky,
Agisoft LLC

btppmc

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Re: not align phots
« Reply #12 on: July 25, 2013, 09:53:31 PM »
I'm having the same trouble, even though I've taken 50+ photos of the same person standing still, Photoscan tries to "align" all of my shots into a clump at the front of the person. As you can guess, the "matching points" cloud is mostly noise, and I don't even get close to anything about model generation.

I've been trying to make Photoscan work for a while now, and I keep getting the same problem.

My model is my wife, who would prefer not to have her pictures on the internet, so I won't post screenshots here, but maybe my workflow is wrong. I put masking tape on the floor in a circle, and then mark 16 points equidistant around that circle. I have my wife or whoever I'm trying to photograph in the center, and then I take shots at each point around the circle, at four different heights - my eye level (6ft), crouching, squatting, and then right against the floor. Each shot overlaps the ones around it, and each shot is taken "flat" (i.e. not tilted, as much as possible) towards the object. I get about one third to one half of the person I'm trying to shoot with each shot; i.e. shot 1a is front, head and upper torso; shot 1b is front, torso and waist, shot 1c is waist and thighs, shot 1d is thighs and feet. Shot 2a is 22.5 degrees counterclockwise of front, head and upper torso, and so on. (They're not named that, though - the images are all just named image001.jpg, 002.jpg. etc., if that makes a difference.) 

I tried loading this selection of shots into Photoscan, but again, the alignment woes I mentioned before. After reading this thread, I tried masking the photos very carefully so that only my wife was in the shots, with the same results - random noise of (very few) points, and the cameras "aligned" in a clump in front of, not around, her.
 
I'm trying this out with a dinky little point and shoot (12 MP), so that may be the problem; with indoor lighting (which is, unfortunately, the lighting I will have to use if I can get this to work for my application.)

I'm going to attempt it with a DSLR later on today, and hopefully that will fix the problem. Otherwise, am I missing anything important? Is there any thing that I am screwing up, theory-wise? (Clearly, I'm screwing up something in practice.)

Thanks so much for any help; it's greatly appreciated.


Alexey Pasumansky

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Re: not align phots
« Reply #13 on: July 25, 2013, 11:23:27 PM »
Hello btppmc,

The problem could be in the quality of images - for example, image blur or high noise level (due to high ISO).
Another problem always appears if you are trying to make scans of living subjects using single camera. Person could be moving slightly and it will cause major alignment and reconstruction problems.

However, probably your wife would not mind if you provide us the image set for internal checks and processing?

P.S. I also recommend to check Full Body Capture tips: http://downloads.agisoft.ru/pdf/Image%20Capture%20Tips%20-%20Full%20Body%20Capture.pdf
Best regards,
Alexey Pasumansky,
Agisoft LLC

btppmc

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Re: not align phots
« Reply #14 on: July 25, 2013, 11:56:04 PM »
Thanks so much everyone - both Alexey Pasumansky's post here and Wishgranter's message (thank you!) helped a ton.

It looks like the autokinetic effect is, at least partially, my undoing; people move a little, even when holding still, and it looks like I'll need to save up for a multi-camera setup to replace what we're doing in our workflow. (Right now, we're using a Kinect for full-body scans, which works... sort of.) Hopefully, the next capture session can pay us enough for us to make the jump from depth-of-field work to photogrammetry.

And Alexey, I think my wife would be ok with sharing photos, as long as they stay internal to your company. I'll send them to you zipped in private message.

Thanks!