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Author Topic: orthophoto from single aerial image and DSM  (Read 2335 times)

RalfH

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orthophoto from single aerial image and DSM
« on: May 30, 2018, 03:58:50 PM »
Is it possible in Photoscan to create an orthophoto from as single aerial image, a DSM and some ground control points? Theoretically, it should work (camera position and orientation computable from ground control points, then projecting the image over the DSM) - but how?
« Last Edit: May 30, 2018, 04:08:37 PM by RalfH »

RalfH

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orthophoto from single aerial image and DSM
« Reply #1 on: May 30, 2018, 04:12:12 PM »
Is it possible in Photoscan to create an orthophoto from a single aerial image, a DSM and some ground control points? Theoretically, it should work (camera position and orientation computable from ground control points, then projecting the image over the DSM) - but how?

Example:
- load image
- import markers with georeferenced XYZ coordinates
- set coordiante system
- try to import DSM --> error: "empty frame path"
« Last Edit: May 30, 2018, 04:28:09 PM by RalfH »

Alexey Pasumansky

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Re: orthophoto from single aerial image and DSM
« Reply #2 on: May 30, 2018, 04:26:11 PM »
Hello RalfH,

To generate the orthomosaic from the single image you need to define the exterior and interior orientation parameters for the camera. So you should have XYZ coordinates of the camera center, yaw, pitch, roll or omega, phi, kappa angles and calibration parameters.
Providing that you specify these parameters and import the surface (DEM or mesh) in the same coordinate space, you would be able to generate the orthophoto.

Unfortunately, currently PhotoScan doesn't support image georeferencing based of the control points (like some GIS application do).
Best regards,
Alexey Pasumansky,
Agisoft LLC

RalfH

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Re: orthophoto from single aerial image and DSM
« Reply #3 on: May 30, 2018, 04:30:52 PM »
Hello Alexey,

thank you. Is there a way that Photoscan can compute camera calibration plus yaw, pitch, roll or omega, phi, kappa from the control points?

SAV

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Re: orthophoto from single aerial image and DSM?
« Reply #4 on: May 31, 2018, 06:06:46 AM »
Hi RalfH,

I don't think that's possible with Photoscan, but Alexey will definitely know the answer.

All the best.

Regards,
SAV