Translate Ortho & DEM by fixed value

[cseaton79]

I need to translate or shift the Orthomosaic & DEM by a fixed value (ie x/y/z in ft: .05, .121, .332) .  I see the option to do that on the Dense Cloud export.  I have successfully done that with the Dense Cloud and can see the shift in my other GIS applications.  I also see the Datum Transformation option, but the Ortho & DEM do not seem to move, even if I apply a very large shift I don't see a change using that option.  Also the Ortho and DEM shows meters, although the Dense Cloud export shift shows ft. (project in FT).

Is there a way to translate or shift the Ortho & DEM?

Thanks,

Chris

[cseaton79]

Note, the images are direct geo-referenced, no markers are used.

[Alexey Pasumansky]

Hello Chris,

Can you please specify, what is the purpose of such shift applied to DEM and Orthomosaic?

[cseaton79]

Hello Alexey,

We receive check points from a survey company in ft, easting northing elevation(the points are not control as the photos are direct geo-referenced, we don't use them for markers/alignment, just to check the drone flight data). After creating and exporting the dense cloud in Metashape, I produce an error report for the dense cloud using the survey company's check points in a 3rd party software.  I note the mean errors and then use those values(usually very minimal, less than 3-4cm with our typical flights) to "align" the dense cloud to the check points(the drone/aircraft data vs survey data) by shifting the dense cloud to the corresponding opposite values on export.  I then re-run error report to verify proper shift. Then the mean error is very near zero, 0.1 cm or less typically.

I would like to be able to shift the Orthomosaic and DEM in the same manner, on export, so that they can be "aligned" with the survey data also. Yes I can re-build the DEM from the shifted Dense Cloud, but of course the Ortho does not shift properly if you use the shifted Dense Cloud(images don't move).


FYI, because we use direct geo-referencing, we have less check points on the ground, so we don't have enough points for typical ground control.  Also we fly very large areas and the direct geo-referencing workflow saves us considerable time on the ground and in some in processing.


Thank You,

Chris

[skj]

Were you able to figure out a way to shift the ortho and DEM by fixed XYZ values?

[Costas]

It is not possible in Agisoft. As you mentioned this is possible only in exporting the Point Cloud.

Workaround method:

1.) Export Dense Point Cloud with the shifts you need. (the values you put are always considered by Metashape as a subtraction. So the use the - (minus) symbol infront of the values accordingly).
2.) Import the exported Dense Cloud to the project.
3.) Build DEM from the new imported Dense Cloud
4.) Build Orthomosaic from new DEM