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Author Topic: Holes in Height Field  (Read 5997 times)

fh

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Holes in Height Field
« on: May 08, 2012, 12:16:42 PM »
Hello

I've got some troubles with height field reconstruction from aerial photos. The building roofs are not reconstructed in some cases, while neighboring roofs of buildings with same size are correctly (see attachment, settings: ultra high, sharp).
Whats the reason for this problem? Is it depending on the parameters P1 and P2? The overlap between the photos should be sufficient (each point of the region is visible on min 4 photos).

When I extract the depth map of the photos, this buildings roofs are clearly visible.

Thanks!
fh

fpbv

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Re: Holes in Height Field
« Reply #1 on: May 08, 2012, 04:38:54 PM »
I had the same problem using sharp, so now I use smooth all the time.
It will fix this.

fh

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Re: Holes in Height Field
« Reply #2 on: May 09, 2012, 08:27:07 AM »
I've tried it with smooth, but the results are the same: Some roofs were not reconstucted.
There are for example 3 neighboring buildings with same shape and roof texture, where 2 of them were correctly reconstucted and one not (see attachment). All of these building are visible on 4 aerial (nadir) photos.

Is there no setting to fix this?

Thanks
fh

fpbv

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Re: Holes in Height Field
« Reply #3 on: May 10, 2012, 04:47:48 AM »
Could you send me these 4 photos?
I will process here and see what happens.
Pm if you want to.

fh

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Re: Holes in Height Field
« Reply #4 on: May 10, 2012, 10:27:18 AM »
@ fpbv: Sent you a pm.

In the attachment the corresponding disparitiy map. All roofs are clearly visibile.
I could reconstruct the scene from this disparity map 'manualy' outside from PS, but its obviously very time-consuming when i have houndreds of photos...


fpbv

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Re: Holes in Height Field
« Reply #5 on: May 10, 2012, 09:29:47 PM »
Hi fh

It worked here, besides some few other building didn?t.
What I did:

- align: accuracy-high
            Pair selection - disabled.

- build geometry: arbitrary - high - smooth
                            face count: 4000000
                            filter threshold: 10
                            hole threshold: 20

And I hope to help you: your photos has a lot shadows, it seems to me you flew past 16:00 o?clock.
I did a flight years ago past 16:00 and my client didn?t accept so I had to flight again, and I tell you, the new photos were way better.
So avoid this, even the day has a beautiful light past 15-16:00 o'clock, don?t do it.

Just tell me which software you are using to have this disparity map because I need this to show do some customers.

Alexey Pasumansky

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Re: Holes in Height Field
« Reply #6 on: May 12, 2012, 03:57:47 PM »
Hello Fabian,

Could you please also send us these photos for testing to support@agisoft.ru?
Best regards,
Alexey Pasumansky,
Agisoft LLC