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Author Topic: How to create DEM and orthomosaic that are exactly coincidental?  (Read 2054 times)

ChrisC

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I have an area where I created a DEM and orthomosaic but when I zoom way in on the pixels I see there is a slight shift (less than a pixel). I need to be able to overlay these products so that a pixel in the DEM is completey coincident with an underlying pixel in the orthomosaic. I have tried several different settings but shifting occurs no matter what. I would think they should be spot on considering they generated from the same source.  Is there something I'm missing?

Alexey Pasumansky

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Re: How to create DEM and orthomosaic that are exactly coincidental?
« Reply #1 on: March 08, 2020, 02:01:47 PM »
Hello ChrisC,

Are you observing the same effect, if the orthomosaic gneeration resolution is set as a same value used for the DEM?

Also how you are checking that shift?
Best regards,
Alexey Pasumansky,
Agisoft LLC

ChrisC

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Re: How to create DEM and orthomosaic that are exactly coincidental?
« Reply #2 on: March 09, 2020, 04:53:00 PM »
Hi Alexey, thanks for responding.

Yes, I am using the same resolution. I Build the DEM from the mesh using the default resolution (0.00135878 m)
Then I build the orthomosaic, click the Metres... button and enter in the same resolution (0.00135878 m)
The created DEM and Orthomosaic both have same resolution (1.36 mm/pix) and the pixel sizes are exactly the same.

I checked for the shift by zooming all the way in and visually checking for difference on screen, double clicking the mosaic and then double clicking the DEM. Thats where I see the shift, less than a pixel. 


ChrisC

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Re: How to create DEM and orthomosaic that are exactly coincidental?
« Reply #3 on: March 16, 2020, 05:36:28 PM »
Alexey, do you have any suggestions about this? Thanks!

ChrisC

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Re: How to create DEM and orthomosaic that are exactly coincidental?
« Reply #4 on: April 01, 2020, 05:09:35 PM »
Anyone have any ideas about this?