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Author Topic: unwanted noise on objects  (Read 12039 times)

JozefP

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unwanted noise on objects
« on: November 19, 2012, 12:14:44 PM »
Hello.

I am still facing one problem with Photoscan. Unwanted noise is still apearing on or arround my generated models and mostly with different shape. To prevent that, I use masks on small objects with few pictures but sometimes is not possible to mask hundred pictures.
I want to ask, if the shape of noise is on each calculation generated constantly or randomly?
Because I mostly get different noise shapes on same generated object.
And I spotted noise also on masked object on some corners where I used masks and in some holes which should be opend but are closed after building geometry.

Thanks
« Last Edit: November 19, 2012, 12:46:49 PM by JozefP »

James

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Re: unwanted noise on objects
« Reply #1 on: November 19, 2012, 02:13:24 PM »
Easy way to mask 100s of images is to align images as well as possible, set bounding box and build geometry on area of interest at very low quality i.e. pointcloud method or low/lowest using smooth method. Once very approximate geometry is built you can import mask using model and then repeat the whole process refining the mask with each iteration.

Wishgranter

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Re: unwanted noise on objects
« Reply #2 on: November 19, 2012, 05:36:46 PM »
Can show some screenshot ?
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mwillis

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Re: unwanted noise on objects
« Reply #3 on: November 20, 2012, 06:00:52 AM »
Easy way to mask 100s of images is to align images as well as possible, set bounding box and build geometry on area of interest at very low quality i.e. pointcloud method or low/lowest using smooth method. Once very approximate geometry is built you can import mask using model and then repeat the whole process refining the mask with each iteration.

James, would you mind detailing this process a little more?  Anything that speeds up the masking process is a welcome bit of knowledge.

Thanks,

Mark

James

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Re: unwanted noise on objects
« Reply #4 on: November 20, 2012, 02:19:02 PM »
It is just a very blunt approach to background removal!

I am not sure if the option exists in Photoscan Standard but in Pro you can import masks from the existing geometry using Tools->Import->Masks... then select "Active Chunk" and "From Model".

If your background is causing problems with your alignment or reconstruction, or you want to force photoscan to find more matches on your subject (guessing that's how it works) you can do a very quick geometry construction, after aligning images as well as you can, and use that geometry to quickly mask out most of the background.

You may need to scan through the photos after you imported the mask to see if any were incorrectly aligned in which case you will need to edit the mask manually.

Now you can align the images again, using the mask constraint, and the masked out background will no longer be taken into account when aligning.

I haven't done any tests yet to confirm whether this increases workflow speed or quality but it did help me align some photos i took of a friend who couldn't stand still... photoscan was aligning images based on the static background because my friend was swaying too much. quickly masked out the background using this approach and the photos aligned much better on his swaying body and i was able to do a reconstruction, although it was still awful... no substitute for a 50 camera rig!

JozefP

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Re: unwanted noise on objects
« Reply #5 on: November 21, 2012, 05:00:56 PM »
Here are the screens. I have no idea how to generate geometry with holes. All 30 pictures are masked.

JozefP

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Re: unwanted noise on objects
« Reply #6 on: November 21, 2012, 05:08:24 PM »
Screens.

Wishgranter

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Re: unwanted noise on objects
« Reply #7 on: November 21, 2012, 06:38:35 PM »
From the screenshots, it seems that you process it on MEDIUM / HIGH, can calculate on ULTRA ?? if yes try it.... and let me know...
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JozefP

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Re: unwanted noise on objects
« Reply #8 on: November 21, 2012, 07:25:47 PM »
It was generated with high settings. I tried it also with ultra high settings but with same result. I need a solution how to maintain the holes like on the real model. Something like mask it but that is not working in this case.

Thanks

Infinite

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Re: unwanted noise on objects
« Reply #9 on: November 21, 2012, 08:01:47 PM »
Even if you have super accurate clean masks, they don't actually help cut or shape the geometry. Unlike silhouette reconstruction methods.

I think it would be fantastic to have such a method integrated into Agisoft. i.e it will use the mask data to help cut and carve out unwanted noisy data.

I get this allot of full body models in fingers, under armpits and between legs that have to be cut out by hand  :'(
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JozefP

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Re: unwanted noise on objects
« Reply #10 on: November 21, 2012, 08:29:16 PM »
Doh!

tezen

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Re: unwanted noise on objects
« Reply #11 on: November 22, 2012, 12:39:40 PM »
+1
Infinites idea is really good to generate a model out of masked areas (of choosen photos) and to use that as a cutter. It could be generated real fast because and without depthinformation/maps its equal to ZBrushes shadowbox (with more than 3 sides). Even better would it be that PS just move the polys/vertexes inside a masked area out to the borders of a masked area (on one or more choosen photos). That would prevent holes. The negative thing is that some surfacedetails will be lost.

@JozefP
Just looked at your project. For objects like that it will help to take some nearby photos of those holes. In most cases you will get a more acceptable result. Some spots on the floor for better lightning should help too. I?ve recognized that darker areas are a little bit problematic.
« Last Edit: November 22, 2012, 12:53:40 PM by tezen »

Mr_Curious

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Re: unwanted noise on objects
« Reply #12 on: November 22, 2012, 03:03:21 PM »
Even if you have super accurate clean masks, they don't actually help cut or shape the geometry. Unlike silhouette reconstruction methods.

I think it would be fantastic to have such a method integrated into Agisoft. i.e it will use the mask data to help cut and carve out unwanted noisy data.

I get this allot of full body models in fingers, under armpits and between legs that have to be cut out by hand  :'(

+1

If you create a lot of models all the time spent in cleaning up this type of noise really adds up, it's a workflow killer.  I have to agree with Infinite, it would be brilliant to have such a method available in Agisoft to remedy this.

Greetings,

Mr. Curious

Infinite

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Re: unwanted noise on objects
« Reply #13 on: November 22, 2012, 04:14:53 PM »
Even if you have super accurate clean masks, they don't actually help cut or shape the geometry. Unlike silhouette reconstruction methods.

I think it would be fantastic to have such a method integrated into Agisoft. i.e it will use the mask data to help cut and carve out unwanted noisy data.

I get this allot of full body models in fingers, under armpits and between legs that have to be cut out by hand  :'(

+1

If you create a lot of models all the time spent in cleaning up this type of noise really adds up, it's a workflow killer.  I have to agree with Infinite, it would be brilliant to have such a method available in Agisoft to remedy this.

Greetings,

Mr. Curious

Might be worth others popping by here and doing a +1 on the feature request if they really need it.

http://www.agisoft.ru/forum/index.php?topic=847.0
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