Image is deformed?

Hello there

I’ve processed 48 pictures that all should be just fine with my P4 but when I stitch them together the result doesn’t look good… What am I doing wrong?

Here’s the photo TIF Orthophoto:

Here’s the 45 photos that was stitched:



Anders Christiansen

I am running a test, but with a cursory look at the imagery, your overlap is close to 60% (visual estimate) which is really low for flying vertical structures like a roof. You need more overlap (77% or more), preferably also an orbit flight that gets some angled shots, and I would get some high shots as well: you are really close to that roof, which is fine if you also get higher shots.


Thank U Smathermather for your kind reply!

Okay I usually fly with 80 % overlap… Maybe I forgot to adjust in this case…! I flew close to the roof to get the best detail quality… I jyst marked an area in GS Pro 2D and flew… Don’t know how to add pictures with higher shots in a mission…

All the best


Mostly: just fly two missions and combine them when processing. Good luck!

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Thank you so much! Do you choose the “hover and take picture” or just taking pictures when it’s on the way…? Yes I’ll try it again tommorrow :wink:

For a P4, I think it has a global shutter, in which you don’t need to hover. With lesser cameras, like the one on the old Mavic Pro, it is better to hover, although acceptable results can be achieved without hovering under many conditions.


Hello again

I went over there again to do a new flight. This time I assured I had 80 % overlap. I flew close to the roof but also another flight double as high as you suggested. the result is better but not even close to something I can deliver to my customer… Do you have any ideas/advise?

You can see the Ortho picture here:

Thank you again!


It would help to elaborate on this statement. Which part(s) of the result do you feel are insufficient? What are your customer’s expectations? It’s easier to discuss and troubleshoot specific items in the output, than just a general statement of “it’s not good enough”.

Thank you for your responce Coreysnipes.

Have you seen the picture I’ve uploaded? Here it’s pretty clear… Many details are wrinkled and blurry and the lines don’t fit…

Will I get a better/more detailed result if I choose 90 % overlap instead of 80 %?

Diminishing returns at some point.

Have you tried taking the imagery off-nadir, maybe 5deg up?

How about cross-hatch flight plan combined with that and the multi-elevation plan?

Good tips. We should do another UAV Arena comparing the ODM outputs from different flight plan & overlap variables.


That’s a great idea.

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I took the images and uploaded it to the platform on Pix4D and that worked… So I guess there’s nothing wrong with the images…

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Then it’s time to iterate upon the various processing settings within WebODM to get the fidelity of output you require!

Did you try to force the camera model to Brown?

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No… where can U do that? :slight_smile:

This option is in the WebODM dashboard under Options when you start a project.

Could you post the image set for the second collect you performed? The first set can not be stitched properly by Microsoft Image Composite Editor successfully, which is usually not a good sign:

As an aside, I also struggled with structures like that building back when I did agricultural field survey. I guess tiepoints are difficult to find on an almost entirely homogenous surface like a (relatively new/clean) roof.

I’d like to test your second collect.

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It says: “Sorry You can not post a link to that post…” Don’t know why…

Try once more, there was some auto-spam-checking in the forum software that was getting in the way. I think I sorted it out.

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