Let's compare ODM! [Data Challenge, earn a badge]

I guess that one reason for the questions about what’s “right” is the use of the orthomosaics in construction. I’ve been operating under the assumption that I can take my orthomosaics made with GCP’s and pass the red face test when sitting with contractors and surveyors who want to know if the data is accurate. By that they really mean “Is it the same result that a land surveyor would get?” Now after running the comparison tool, I don’t know what I think about that question.

I’ve done a handful of mapping jobs for construction using DD as well Pix4dMapper, and am in the process of getting up to speed on ODM as my go-to affordable solution. Now I’m uncertain whether I really want to be in this market segment (drone mapping for construction).

Now I’m really pulling off topic, so time to stop.

1 Like

The way the data is collected matters too. Non of these jobs we processed would have been good enough to say “Here’s some really accurate data”.

But it also depends how accurate they want it!

GCPs and proper flight plans (and other factors) give good absolute data.
Equally, proper flight plans (and other factors) give good relative data.

1 Like

Agree. I had assumed that when I used best practices and GCP’s, that my data was accurate. Now I see that when identical data is processed through different engines and the orthomosaics are compared with the slider in the Mapping Arena, that they’re largely the same, but not exactly the same. So now I’m worried about the accuracy of my deliverables.

1 Like

I also see that the delivered DEM’s don’t employ the same color palettes. How do those different color schemes get converted into the same contours or into equivalent inputs into CAD programs? I can see where this comparison data challenge can start abuncha follow on threads to explore questions. Oh Man! Maybe I should just enjoy playing with the Mapping Arena and not worry about “What Does It All Mean”. Accept that everything has variation and roll with it.

1 Like

I’m feeling like Columbo with ‘One more thing’. If I wanted to explore some of the differences between deliverables in more detail, can someone point me to a good process for setting up a comparison like pierotofy has done in the Arena. I’d like to spend some time insuring that I’m comparing identical scales with exact overlays, but programming and GitHub are not my superpower. Any recommendations are appreciated. Thanks… bob r.

1 Like

Good morning, thanks for the exercise, I would like to know if it is possible that you can share the set of configurations with which it was processed in the ODM software. Thank you very much I remain attentive to your comments

2 Likes

Agreed. This is a pretty interesting set of comparisons. I haven’t seen anything like it outside academic photogrammetric comparisons, and certainly not with such a wide swath of drone imagery processing software.

To that end, be sure to compare data in the middle. There are different automated cropping algorithms and different kinds of bias and error along the edges of these datasets, which affects the perception of differences. For these smaller datasets, this is even more apparent.

2 Likes

What a fantastic idea! I love the slider-comparison!
I noticed that sandy key is still available for Metashape, is that right? I can run it.
Are you guys planning on publishing the results?

What about Alice Vision/Meshroom? should it be included?

2 Likes

Alice Vision/Meshroom would make a very interesting addition.

2 Likes

I’m up for running a Meshroom comparison, but I’ve only used it once so I wouldn’t know initially what settings to use.

1 Like

I’ll do it (already doing it)

3 Likes

Here it is. Dropbox - Error - Simplify your life
sand keys processed in Metashape Pro 1.6.2 (linux) in “medium” quality both for Sparse and Dense Clouds. Files exported with 2cm/px, UTM 17N (DEM, Ortho) + LAS.
I’ll try to run it in “high” tonight (my laptop will need a couple of hours for this…)

2 Likes

Done. Dropbox - Error - Simplify your life
sand keys processed in Metashape Pro 1.6.2 (linux) in “high” quality both for Sparse and Dense Clouds. Files exported with 2cm/px, UTM 17N (DEM, Ortho) + LAS.

2 Likes

Excellent idea! Thank you. Another data processing app that seems to be favorited is Maps Made Easy, especially for ortho’s.

1 Like

I’m processing these data sets in Maps Made Easy. The Aukerman dataset actually required me to spend some points since the images were taken with an 18 MP camera. Not many and I had a few left over from an old project.

1 Like

So MME does not export to map tiles, instead, I get an orthomosaic in one file. I’m not sure how to split that up into tiles. In Agisoft Metashape, you’re supposed to be able to import an orthomosaic, but it fails when I try to import these files. I’ve got Sand Key and Brighton Beach done, but am still waiting for Aukerman to finish. Aukerman took longer than I expected in Agisoft Metashape on my mapping system too. The MME files are here, and I’ll add Aukerman as soon as I get notified that it is finished.

[Update] Aukeman finished and has been added.

https://drive.google.com/drive/folders/1IWLaZG5t8wBmrVzTXvMhZiQcGTwwqbTk?usp=sharing

I always thought MME makes some nice maps, but looking at the orthos produce with these test datasets, these are the worst of all of them that I’ve looked at. And, they completely lack the ability to export map tiles: Maps Made Easy - Outputs

Speaking of Agisoft Metashape, I just ran all three datasets in Metashape 1.6.3 which as of today is the latest version. The only problem is, when I export them to map tiles, the files are MUCH larger than even the Pix4D files (Pix4D data comes in at about 100 MB) and weigh in at a total of 1.12 GB. I’m not sure what settings others have used for exporting in Agisoft Metashape, but since I have very limited space on my Google drive, I don’t want to upload those until I get it figured out.

Chances are Agisoft isn’t using compression in the TIFF. You can compress it by converting with GDAL. The following should be adequate:

gdal_translate \
  -co COMPRESS=LZW \
  -co TILED=YES \
  input.tif output.tif
1 Like

Hi all!

UAV arena is great! I would like to know if it is only done for this test or to implement it as a tool in the future (inside or outside ODM)?

Please @Jeff_Gaudette, which plugin do you mean by QGIS? I would like to have it.

Again, thank you very much and great job!

Regards,

Hello @tatowem,

The plugin I am referring to is Mapswipe.
This youtube video explains what it does and how to install it.

Enjoy!

Jeff

4 Likes

Thank you! This is just what I needed for a project I’m working on.

1 Like