Actual photo overlap and Report photo overlap - different?

[aggieair]

Normally we are used to projects with planned UAV flights and recorded flight log info.

Currently I'm on a historical aerial imagery project.  Images were scanned at 1200 dpi on a large format reflective scanner.  No flight log or orientation info was include - purely paper maps only. Markers were extracted from LiDAR information for orthorectification.

See my attached photos.  Laying the images out on the floor shows decent overlap.  The point cloud is decent and it makes a decent looking mosaic in ArcGIS.

However, in the report PDF, it looks like awful overlap and an awful mosaic.  Any reason to this?  I need to assess 24 individual projects for overlap success and was hoping to just glance at the PDF report rather than laying out hundreds of images all over again.  Agisoft projects have been started for all a generating a report is possible.  I just want to be sure its reporting it correctly.

Can anyone clarify this?

[Alexey Pasumansky]

Hello aggieair,

And is there a mesh generated for this project? Whether it is complete?

[aggieair]

Hi Alexey, didn't think you'd be awake!

Yes a Mesh was generated for this project (and all projects, this was before I knew about the DEM-derived option in 1.2.0).  I believe it is complete, but otherwise how is that indicated?  Used HIGH face count on a LOW dense cloud.

I did however, continue this project (after the software upgrade) with the Build DEM and Build Orthomosaic options, but it hung on to the Mesh from the original version.

UPDATE: just reran the mesh (just in case) and made another report.  Same result.

[aggieair]

Ok, this is interesting.

I already had an old .psz project for this same project (this is before I was aware of the version upgrade).  Version 1.6.X something.

WHen I learned of the newer Agisoft version, I opened this old .psz and saved as .psx.  The outputs from that .psx are what I posted in the original post.

Attached in this post is the report image overlap I made from that old .psz project where I the mosaic was mesh-derived, not dem-derived.

So it cares if the mosaic is made from the mesh to get a proper overlap image?

[Alexey Pasumansky]

Hello aggieair,

Maybe you can send the PSZ file to support@agisoft.com and we'll check what could be wrong in 1.2?

[Alexey Pasumansky]

Hello aggieair,

We've received the images, but not the project files. Could you please resave them in PSZ format, as PSX file without the corresponding .files folder is not useful.

[aggieair]

Agisoft checked it out and said "It seems that the issue has been related to the feet used as geographic coordinate system units. Will add the fix to the next version update" in case anyone was following or will look this up later.