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Author Topic: Marker errors compared to model  (Read 998 times)

dronesurveyconsultancy

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Marker errors compared to model
« on: December 24, 2019, 06:34:41 PM »
Hello everyone,

I was wondering why in the reference panel my markers are displaying very small errors.
When i import my pointcloud into autocad and checking my point cloud to my measured points i have errors much bigger than agisoft is telling me in the Z axis.  Using 1.5.5.

Anyone have an opinion or ideas?

Greetings and best of wishes

Alexey Pasumansky

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Re: Marker errors compared to model
« Reply #1 on: December 24, 2019, 08:21:38 PM »
Hello dronesurveyconsultancy,

Please see my post regarding this change in another thread:
https://www.agisoft.com/forum/index.php?topic=11329.msg50857#msg50857

Quote
In Metashape Pro (and PhotoScan Pro) versions prior to 1.5.4 estimated control point coordinates displayed in the Reference pane (and the error values as well) were calculated based on minimization of the reprojection error only, without taking into account measured control point coordinates in space. So they did not correspond to adjusted coordinates from the bundle adjustment step, and were recalculated from weighted image measurements alone.
 
Starting from Metashape Pro version 1.5.4 estimated control point coordinates correspond to the adjusted values, that is, they are calculated taking into account both reprojection error and measured object space coordinates. Similar behavior is common for other software packages and also allows for better detection of the measurement errors.

If you are interested in the difference between measured and triangulated control point coordinates, you can temporary uncheck the corresponding entry in the reference pane (thus making it a check point). Please note that check point error calculation is not affected by the change mentioned above. Upon unchecking the control points you do not have to click on Update button.

You can use Check points, however, to disable the adjusted values consideration. If you have only Control points, you can uncheck them in the pane and observe such errors (do not click on Update button on the Reference pane toolbar).
Best regards,
Alexey Pasumansky,
Agisoft LLC