forestry ortho mapping tree blur

[FSLpilot]

Hi there I am currently using a Mavic 3 Enterprise for forestry ortho mapping and having issues with blur of pine trees

Flying at 120m (highest allowed in NZ under 101) and have played around with changing overlaps and haven't noticed a change in results.

Using WebODM for processing

Interested to hear what other people have been using to get better results, from overlap ratio, elevation settings and ortho mapping software to get better results

 

[Meta4]

Hi there I am currently using a Mavic 3 Enterprise for forestry ortho mapping and having issues with blur of pine trees

Flying at 120m (highest allowed in NZ under 101) and have played around with changing overlaps and haven't noticed a change in results.

Using WebODM for processing

Interested to hear what other people have been using to get better results, from overlap ratio, elevation settings and ortho mapping software to get better results

Are you getting blurred individual images or is the issue that the photogrammetry software is having trouble stitching properly.

Can you upload a full-sized original image to Google Drive or similar and post a link here.

 

[AMann]

Hello and welcome!
Wow, that’s a tough one for most any program to rectify and is certainly not an “ortho” map. I’d be happy to try a sample of it with my Agisoft Metashape program as a comparison. See if you can save a few overlapping sets of your original image files and post the link to them here as Meta4 suggested.

 

[FSLpilot]

Are you getting blurred individual images or is the issue that the photogrammetry software is having trouble stitching properly.

Can you upload a full-sized original image to Google Drive or similar and post a link here.

It is predominantly the photogrammetry software as the actual individual images don't have blur. I wouldn't be able to share the full photo due to client confidentiality but will see if I can get permission in a forest for this sample purpose

 

[FSLpilot]

Hello and welcome!
Wow, that’s a tough one for most any program to rectify and is certainly not an “ortho” map. I’d be happy to try a sample of it with my Agisoft Metashape program as a comparison. See if you can save a few overlapping sets of your original image files and post the link to them here as Meta4 suggested.

I have heard Agisoft Metashape may have some tool that could help. Wouldn't be able to share all the original images due to client confidentiality but will try get permission to a forest for a sample purpose

 

[Meta4]

It is predominantly the photogrammetry software as the actual individual images don't have blur. I wouldn't be able to share the full photo due to client confidentiality but will see if I can get permission in a forest for this sample purpose

Forest canopy is always difficult for the stitching because it's hard to identify matching pairs of points out of thousands of branches that all look alike.
The usual tips for working in that environment are to work from a greater height and use more overlap, but it sounds like you've already done that.

 

[tstr14]

Forest canopy is always difficult for the stitching because it's hard to identify matching pairs of points out of thousands of branches that all look alike.
The usual tips for working in that environment are to work from a greater height and use more overlap, but it sounds like you've already done that.

Since he's already at max height, would a wide angle lens help? It would have the same effect as flying higher, would it not?

 

[Meta4]

Since he's already at max height, would a wide angle lens help? It would have the same effect as flying higher, would it not?

A high quality lens with a wider angle of view would be the equivalent of flying at a greater height.
That might help with the stitching issue, or it might not.
I don't have one of the slip on supplementary wide lenses to check, but I don't have much confidence that it would provide the kind of image quality required for mapping missions.provide

 

[millbah]

Using my MA2 with Dronelink & processing with Agisoft to get an ortho image, I usually have the tree blur. I also find roof edges have a blur effect. In my case it is not significant & I live with it.

 

[Kilrah]

Wider angle lens is often worse for stitching because of the distorsion both of the lens and of the perspective shift. The camera may see a tree in more shots, but some will be from the top and some from the side and the software will have no idea it's the same thing/no way to merge them.

 

[AMann]

Another problem is parallax. As Meta4 suggests you need more overlap than usual, much more overlap. Because of the height of the trees, even slight drone movements will exaggerate the difference in distance between the tree tops to the tree bases. I would do as much as an 80% overlap as a test. I know that’s gonna take a long time to shoot but start testing a sample with a large overlap and then work it down until you get a suitable balance between time and number of files vs overlap

 

[ssb73q]

I also have issues with WebODM stitching trees, especially when it is windy. Doing crosshatch missions helps sometimes, but I often have map image holes after stitching photos with WebODM.