Agisoft Metashape

Agisoft Metashape => General => Topic started by: trevman on July 17, 2016, 09:39:37 PM

Title: Mosaic being saved upside down
Post by: trevman on July 17, 2016, 09:39:37 PM
Hi everyone!

I am trying to map a small area aligning 128 photos (not georeferenced, just jpg pictures) taken by my drone. The best I can do is to create a mosaic, but it goes upside down whenever I try to export it (save it as tiff or jpeg). I have tried so many ways to get it in a proper position axis, but no success. Any help? Please! :(
Title: Re: Mosaic being saved upside down
Post by: stihl on July 17, 2016, 10:18:18 PM
Hi Trevman,

In the reference settings, did you set your project to the right coordinate system? If your drone images have a geolocation in the exif data, Photoscan will usually use this information automatically.  You'll probably need the WGS84 (epsg 4326) coordinate system if this is the case.

If the project is completely unreferenced then it either has to do with the mesh (bounding box heightfield issue) or settings in the Ortho export window.

Can you share some more information and a screenshot of your workspace with the mesh in the view window?
Title: Re: Mosaic being saved upside down
Post by: Alexey Pasumansky on July 18, 2016, 10:07:01 AM
Hello trevman,

When the project is not georeferenced there is a big chance that Z axis will be pointing beneath the real world ground plane (parallel to the camera looking direction). In case the real dimensions do not matter for you you can use one of the following workarounds: export orthomosaic in Bottom XY projection or at first use Rotate Object tool to bring the orientation of the model to the correct one in the coordinate system space.
Title: Re: Mosaic being saved upside down
Post by: trevman on July 18, 2016, 07:06:23 PM
No chance at all! I have tried to export orthomosaic on: MENU FILE - EXPORT ORTHOMOSAIC, but I can't go any further because the option EXPORT JPEG/TIFF/PNG is not serviceable.

Now I am going to try it using WGS84 coordinate system as mentioned and see how it goes.

Remember that my photos HAVE NO coordinate values at all.

I really need your help, guys. Thanks!

Title: Re: Mosaic being saved upside down
Post by: Alexey Pasumansky on July 18, 2016, 09:37:04 PM
Hello trevman,

Before exporting orthomosaic it should be generated using Build Orthomosaic option in the Workflow menu.
Title: Re: Mosaic being saved upside down
Post by: trevman on July 19, 2016, 07:02:37 AM
Could you please show me step by step? Just to ensure a proper process as it demands a long time to get all photos aligned.

Many thanks.
Title: Re: Mosaic being saved upside down
Post by: Alexey Pasumansky on July 19, 2016, 07:12:02 AM
Hello trevman,

You can make a quick test:

- Align Photos (High accuracy, Generic preselection, 40 000 key point limit, 10 000 tie point limit),
- use Rotate Object tool to position the model correctly in the coordinate system space,
- Build Mesh based on Sparse cloud,
- Build Orthomosaic (use 4096 max resolution, for example).

If you see that everything is ok on the Orth view (to switch to the view double-click on the orthomosaic label in the Workspace pane) you can build dense cloud (keeping the same alignment results) in Medium quality, for example, and them build mesh based on that dense cloud.
Title: Re: Mosaic being saved upside down
Post by: trevman on July 19, 2016, 03:17:57 PM
Ok! Here I go...
Title: Re: Mosaic being saved upside down
Post by: trevman on July 19, 2016, 04:33:57 PM
Ok, guys! I got it! I have changed "Top XY" to "Bottom XY" on Workflow - Build orthomosaic - Projection plane.

Thank you guys for your efforts!

That's all folks!  ;D