Fail to generate orthophto from low height (30 meter) images

Hi all,

I used a programmed DJI mavic 2 to collect images of a maize field at 30m high.

I have tried ODM with min-num-features 800,1000,8000,18000, but they all failed to generate the ortho.

I also tried Autopano Giga but it didn’t work either.

What may cause this, and what other parameters should I try?

The images are in the link below.

https://drive.google.com/drive/folders/1n4lCMTdufTDOGJXrEJKLUT6kNvL8v9kj

You can try to increase --matching-neighbors and --matching-distance. But this looks like a difficult dataset to stitch. Make sure you are not resizing your images (disable resize if you’re using WebODM and increase --resize-to). Increase --min-num-features to 28000. Flying at a higher altitude would give you better results (if that’s an option, not sure what resolution you need).

1 Like

@pierotofy Thanks for your suggestion, Piero. I have some more questions:
1.What would be a reasonable value setting of --matching-neighbors and --matching-distance ? Is there any relation with flight height and the optimal values? (e.g, 2x these parameters when 1/2x the height)
2.These images are taken in a parallel route, is it better to have a cross pattern rather than parallel lines, especially in low altitude cases?