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Messages - ArnauCM

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16
General / Re: Micasense panel QR code not visible: how to manually locate
« on: September 21, 2020, 05:34:47 PM »
Hi,

You can manually add your reflectance values in the same window, on the right side.

Follow the section Apendix A from this PDF and you should be fine:

https://www.agisoft.com/pdf/PS_1.4_(IL)_Refelctance_Calibration.pdf

Cheers!

17
General / Re: GCPs in Multispectral chunks
« on: July 23, 2018, 04:18:05 PM »
Hi again!

Any idea about this?

18
General / Re: Huge Problems
« on: July 20, 2018, 06:18:17 PM »
Hello Andre,

Have you tried to mask the background? It is as simple as taking one last picture WITHOUT the object you are modeling, and indicating Agisoft that THIS picture is the background, so that it can mask it automagically from all the other 120 images.

Hope you get better results now ;)

Best,

ArnauCM

19
General / GCPs in Multispectral chunks
« on: July 18, 2018, 08:48:29 PM »
Hello, Community experts,

I am working with multispectral imagery for the first time.

When I was manually pinning the GCPs in the pics I realized that they were only being set in the band I had as a 'Primary Channel' in that precise moment. If I change the band, the markers have to be replaced. It makes sense because there are 5 sets of images from 5 different bands from 5 different cameras (Rededge MicaSense).

My question is then: Should I put the markers 5 times? One for each band to then be able to export precise georeferenced orthomosaics for each band?

I hope I made myself clear as it is somehow difficult to explain. If not, tell me and I will rephrase it.

Thanks!

20
General / Re: Bowl-shaped distortion in DEM
« on: July 18, 2018, 08:33:23 PM »
As always, thank you very much Alexey!

21
General / Re: Bowl-shaped distortion in DEM
« on: July 17, 2018, 06:58:36 PM »
Hello Alexey,

Yes, I include the cameras in the optimization, as I though that I wanted all of them corrected.

Aparently, there are no errors regarding GCP coordinate info. I can see a small change when checking/unchecking cameras and pressing 'update'; a small tild in the X,Y plane.

22
General / Re: Bowl-shaped distortion in DEM
« on: July 16, 2018, 08:25:32 PM »
Hi all,

Ironically I am getting the opposite effect. I add pictures with GPS info from the drone, I align them and the model is amazingly flat, almost perfect one would say. Then, I pin my GCPs and add accurate GPS info (0,3m), update and optimize cameras and... Bowl effect.

What am I missing?

23
General / Re: Will there be any benefit from upgrading CPUs?
« on: June 08, 2018, 05:19:26 PM »
Hi BigCapitalist,

Maybe you are also interested in this article from Puget Systems about AgiSoft and CPU Performance.

Even though you can see improvements rising both clock speed and threads, at the end of the day, higher clock speeds turn into shorter processing times. In fact, you can see in the article how an AMD Threadripper 1950X with 32 threads is almost always beaten by, for example, an i9-7900X with "just" 20 threads but higher clock speeds.

Also, take @SAV 's advice into account. Sometimes, if you are in a budget, it will be better to buy a second GPU rather than spending $1K in a new CPU.

I hope you have now a bit more information to make a better decision. :)

Best,

ArnauCM

24
General / Re: How to put model "on the ground"
« on: May 22, 2018, 03:46:48 PM »
Hi nicokalo,

As far as I know, it is all about the bounding box. You should align your ground to the darkest (grey) face of the box, as that is what AgiSoft uses to determine it.

Hope it is helpful :)

All the best,

ArnauCM

25
General / Re: Depth Filter Advice
« on: May 10, 2018, 09:23:22 PM »
Hi ArnauCM,

Yes, would be great to see how it turned out. But I guess that there will be a lot of noise in your dense point cloud.

Well, it finished! After 120h. Now I have 177M Points and I am building the mesh. It was all done in a MBPro with just 16GB RAM... I am pretty impressed it didn't run out of memory, even if when checking Activity Monitor it was showing AgiSoft consuming up to 60GB of RAM.

That's the paper I was referring to:
James, M. R., & Robson, S. (2014). Mitigating systematic error in topographic models derived from UAV and ground-based image networks. Earth Surface Processes and Landforms, 39(10), 1413–1420. https://doi.org/10.1002/esp.3609

Thank you very much! I will have a look at it :)

Have you tried to extract height measurements using CloudCompare?

How is that different/better than the DEM built through AgiSoft?

Thanks again SAV :)

26
General / Re: Depth Filter Advice
« on: May 09, 2018, 05:52:46 PM »
Hi @SAV and @JMR,

Thank you very much for your answers and advices. Really appreciate them!

In this case it is better to use slightly oblique shots and/or cross pattern flight to get better sight of the ground rather than to use an exaggerated overlap. In addition, exaggerated overlap carries another problem which you are facing now... too much images to process.

Yeah, that's actually what we did. We flought twice, first vertically at 25m and then horizontally at 30m, trying to follow a grid pattern.

I recommend to compute your dense point cloud at MEDIUM or even LOW quality settings due to the low quality of your dataset. Processing it at HIGH or ULTRA probably won't deliver better results .... and you would not have to wait 3 days and 12 hours to get to 54%  ;)

For the results... well that's sad to hear  :(. Now I am not going to stop it, though. Just let it finish and see what the results are. I'll post a result if you want.

If you want to make a good estimation of the tree crown height, I would try to add manual tie points (markers without coordinates) by picking the very tip of each tree in their extreme positions along a pass. I mean, pinning it in the first photo it appears close to the photo frame, and the same in the last one just before it gets out of the camera field of view.
If you do this operation a number of times, you can infer the amount by which you could correct the value of the peaks that result from the analysis of a dense filtered cloud, which typically underestimates the actual height of the trees.

I did that too. Despite of having just 5 georeferenced points I manually pinned up to 20 markers to make sure it was as accurate and compact as possible.

As mentioned by JMR, I would also recommend to change your survey layout to a double grid (perpendicular flight lines) with slightly oblique imagery (convergent imaging geometry, as suggested by James et al 2014).

That is something I didn't know. Could you tell me the name of the paper :)?

Good thing is that it was a test flight to test and adjust flight patterns, and also see what AgiSoft was capable of. For the real data we will take 24MPx, georeferenced pictures (not video) with a lot more georeferenced GCPs. I'll have a look at the paper and see how oblique should the camera be. If you have any early advice though, I will gladly take it.

Thanks a lot!

27
General / Re: Depth Filter Advice
« on: May 08, 2018, 04:47:12 PM »
Hi SAV,

As always, thanks for your help.

Indeed it was a very windy day, with winds of about 8m/s... moreover, the pics are in fact frames from a 4K video, so not really good quality images. On top of it, pics have no GPS data, so it was all relaying on Generic. Accounting all of this, I find quite amazing that photoscan could align 100% of the more than thousand images.

We are now in the middle of the Dense Cloud Point Generation. It has been 3 days 12h so far and 54%. Lets see if we can have it by the end of the week!

Thanks again SAV

28
General / Depth Filter Advice
« on: May 04, 2018, 09:07:48 PM »
Hi community,

I've got this project where we try to model vegetation to get height as much accurate as we can. The pics are just 8MPx each but there is more than 90% overlap. However there is a lot of detail. You can see pics attached. So:

- I managed to get 1073 pics aligned with over 1,3M Tie Points.
- I run the Dense Cloud Point in Medium with Depth filter disabled. Also, the bounding box got moved at some point and I didn't realised and I end up having lots of points under the floor.

So, two questions arise:

- If I run the dense cloud point again with the bounding box correctly aligned to the floor, will all those underfloor points be fitted over the floor, and by so, I will get more detail?

- As you read, I run the DCP with depth filter disabled. If I set it to Mild, do you think I will lose some heigh detail? There are small branches on the top that might get cut by the filter?

So... what do you think? Thanks in advance!

29
General / Re: Manually introducing Camera Model
« on: May 01, 2018, 05:14:50 PM »
Hi SAV,

Thanks for your reply. So that's all Agisoft takes into account? Just Focal length and type of frame? Because there is nothing else I can add as input.

30
Bug Reports / Re: Input Video BUG
« on: May 01, 2018, 04:07:19 PM »
Hi!

Thanks for the replay :)

I am using 10.13.4. I am afraid that the problem might be due to playing with eGPUs and all the workaround that still today must be done through scripts in order to make an NVIDIA eGPU work in macOS.

I suspect this because, when trying to extract frames from the same video using Video Lan Client it happens the same. Even if I use a 2 sec, 60frame max video. However, I could finally do it with Photoshop so... I am safe by now.

If official eGPU support for NVIDIA cards ever come to apple, I will make a clean install and try it again.

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