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Author Topic: Holes in tie points/ depth maps in random portions of images  (Read 6682 times)

skretz

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Holes in tie points/ depth maps in random portions of images
« on: November 17, 2023, 05:45:18 PM »
Hello, this has been an issue in the newer versions of Metashape.  I  haven't had these issues in other software packages like Context Capture.

These are UAV and DSLR photos of a large masonry structure, with lots of great texture for photogrammetry.

I have added images of the results in the mesh (lumpy filled in voids from further away photos). I have added a photo of the image in question, which is super dense with tie points, minus a void with no tie points, the adjacent image showing the same area full of tie points, and the depth map of the image with the void.

Any insight would be helpful.  It has occurred in maybe a dozen spots on this large complex. It doesn't translate into much of an issue in the final ortho photo of each elevation, but it's an annoyance, and ideally would like to have it resolved for future projects.

Alexey Pasumansky

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Re: Holes in tie points/ depth maps in random portions of images
« Reply #1 on: November 17, 2023, 07:16:48 PM »
Hello skretz,

If there are masks applied to some images, do you use "strict volumetric masks" for the mesh generation?
Best regards,
Alexey Pasumansky,
Agisoft LLC

skretz

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Re: Holes in tie points/ depth maps in random portions of images
« Reply #2 on: November 17, 2023, 09:21:44 PM »
Hi Alexey, there's no masks anywhere in the project.  These weird gaps in the tie points are only in a handful of images.  It has happened to me on other projects as well. When there's no tie points, it also has a problem calculating the depth.
This has only happened on more recent versions the last few years. Never had this issue before.  I've tried changing tie point and key point's and re-aligning, but the software just doesn't like those portions of the images.

Alexey Pasumansky

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Re: Holes in tie points/ depth maps in random portions of images
« Reply #3 on: November 22, 2023, 12:50:30 PM »
Hello skretz,

Can you also provide the screenshot of the depth maps for the first image (with no gaps in tie points) and View Matches dialog for KP_UAV-B1-8_June-2023-0946 paired with the image with the biggest number of total tie points? Also specify the parameters used for the camera alignment.

It would be also helpful for analysis, if you can share any sample project with the similar problem (project with the alignment results and related source images).
Best regards,
Alexey Pasumansky,
Agisoft LLC

skretz

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Re: Holes in tie points/ depth maps in random portions of images
« Reply #4 on: January 04, 2024, 04:24:23 PM »
Sorry for the delay,  here's the requested images. I can't think of other projects off hand, but have seen this phenomenon before with the newer versions of the software. Never the older ones.