Forum

Author Topic: Orthophoto generation : source from DEM or Mesh ?  (Read 2568 times)

lmatteo

  • Newbie
  • *
  • Posts: 8
    • View Profile
Orthophoto generation : source from DEM or Mesh ?
« on: March 19, 2019, 01:35:21 PM »
Hello there,

I was asking myself about orthophoto generation with drone's photos :
Is it better to generate an orthophoto from DEM (generated from the dense cloud point) or from the mesh ?

Thank's in advance
Best,
« Last Edit: March 22, 2019, 12:29:31 PM by lmatteo »

lmatteo

  • Newbie
  • *
  • Posts: 8
    • View Profile
Re: Orthophoto generation : source from DEM or Mesh ?
« Reply #1 on: March 22, 2019, 12:30:00 PM »
Anyone can help me please? :)
Thank's !

Alexey Pasumansky

  • Agisoft Technical Support
  • Hero Member
  • *****
  • Posts: 14813
    • View Profile
Re: Orthophoto generation : source from DEM or Mesh ?
« Reply #2 on: March 22, 2019, 01:47:48 PM »
Hello lmatteo,

Usually wee recommend to generate DEM from the dense cloud and use this surface as input for the orthomosaic generation, thus the meshing step can be skipped.

For very large areas most likely it wouldn't be possible to generate a single-block mesh, therefore the DEM is recommended for large areas covered.

Using Mesh surface may be reasonable for custom plane projections (like building facades, for example) or for small areas, when mesh surface produce more accurate results, for example, by the edges of the roofs.
Best regards,
Alexey Pasumansky,
Agisoft LLC

lmatteo

  • Newbie
  • *
  • Posts: 8
    • View Profile
Re: Orthophoto generation : source from DEM or Mesh ?
« Reply #3 on: March 22, 2019, 06:22:19 PM »
Thank you very much for your answer !
I was asking this because I have a very large area and as you said, it's impossible to generate a single-block mesh and so, skip this step is great for me :D !

Thank's again

Alexey Pasumansky

  • Agisoft Technical Support
  • Hero Member
  • *****
  • Posts: 14813
    • View Profile
Re: Orthophoto generation : source from DEM or Mesh ?
« Reply #4 on: March 22, 2019, 07:02:53 PM »
Hello lmatteo,

In the version 1.5 it is possible, however, to generate the tiled model and then build DEM from it. In case you'll be experimenting with the tiled model generation, you can try to compare the orthomosaic outputs based on DEM from dense cloud and from the tiled model.
Best regards,
Alexey Pasumansky,
Agisoft LLC