Generating Orthophoto without generating mesh

[Ingsayyad]

We want to generate orthophoto from UAV images and getting problem that the quality of the orthophoto is not good. Obviously, it depends on the quality of mesh. We do not want to spend to much time to improve the quality of mesh.
Therefore, the question is that can we get orthophoto  without generating mesh.
 The workflow  can be
1: alignment of images
2: getting sparse points
3: projecting 3D points to each image
4: getting  pixel->3D projection
5:Rectify each image individually
6: Making mosaic
Is it possible in PS.
How can I get shape eadges in PS.
Do some body know some other software which implement this.

[Alexey Pasumansky]

Hello Ingsayyad,

After alignment stage you get sparse point cloud, consisting of the valid tie points, for each point in the sparse cloud there's a set of projections on the individual images. Also you've got extrinsic and intrinsic orientation for the aligned cameras.
Could you please specify whether this data is sufficient for your needs, or probably provide some details regarding fifth step of the workflow you've mentioned?

Also note that in the next version of PhotoScan it would be possible to generate DEM from the dense cloud and create an orthophoto based on the DEM. So mesh generation stage could be skipped.

[Ingsayyad]

Thanks for your reply.

How can I export

Image nr    pixel  (x y)  3Dpoint (X YZ) 

In PS there is no way to do so.

Regarding point 5:
I mean to say that after getting  after getting required info [Image nr    pixel  (x y)  3Dpoint (X YZ)  ] of few pixels in an image, 3D coordinates of all the pixels of the image can be calculated. This 3D coordinates are then projected to the required plane and a single orthophoto should be possible.

[Alexey Pasumansky]

Hello Ingsayyad,

Apart from creating the custom script, you can use camera export to bundler.out format, that should contain all the required data, but in a different representation: https://www.cs.cornell.edu/~snavely/bundler/bundler-v0.4-manual.html#S6

[Ingsayyad]

Can I make ortophoto  without using mesh in Bundler?

[Alexey Pasumansky]

Hello Ingsayyad,

I haven't meant to use Bundler or mesh at all. I mean that there's camera export format that also saves information about sparse cloud points coordinates and projections.

[Ingsayyad]

1-Is there any possibility to pre-view the orthophoto.

[Alexey Pasumansky]

Hello Ingsayyad,

In the next version of PhotoScan Pro it will be possible to store and view orthophoto and DEM in PhotoScan project. Also seamline editing instruments will be implemented.

[Ingsayyad]

When should we expect the  new version of PS.

[Alexey Pasumansky]

I hope that pre-release will be published on forum in the next couple of weeks.