Hello,

I'm a researcher that work on a photogrammetry platform developped for specific purpose (underwater exploration, ...) and i use for a time AgiSoft Photoscan for many time now.

The specific platform that i use has to deal with Agisoft Photoscan and has to be able to import / export data from / to your software.

My problem is that the camera model we use in our platform is the PhotoModeler model and i have to export it within Agisoft Photoscan model.

I know that the Agi Lens software can import a PhotoModeler camera and convert it to Photoscan Camera calibration. However, i have to make this conversion inside my platform and i can't use AgiLens at his time.

So here is my (pragmatic) question: How to pass from a photomodeler camera to a photoscan camera calibration ?

Here is one example:

**Photomodeler parameters:***PM*_{wp} Image width, pixel: 1936*PM*_{hp} Image height, pixel: 1456*PM*_{focal} Focal length, mm: 28.7486*PM*_{fw} Format width, mm: 36.1885*PM*_{fh} Format height, mm: 24.112*PM*_{ppx} Principal point X, mm: 17.9828*PM*_{ppy} Principal point Y, mm: 11.4851*PM*_{K1} Radial distortion K1: 0.0001246*PM*_{K2} Radial distortion K2: -1.909e-07*PM*_{K3} Radial distortion K3: 1.172e-10*PM*_{P1} Decentering distortion P1: -2.766e-06*PM*_{P2} Decentering distortion P2: -1.535e-05

**Agi Lens converted camera parameters:***PS*_{wp} Image Width: 1936*PS*_{hp} Image height: 1456*PS*_{fx} Focal length (x): 1537.92*PS*_{fy} Focal length (y): 1735.91*PS*_{cx} Principal point (x): 962.039*PS*_{cy} Principal point (y): 693.533*PS*_{skew} Skew: 2.01075e-05*PS*_{K1} Radial K1: -0.101602*PS*_{K2} Radial K2: 0.147258*PS*_{K3} Radial K3: -0.112404*PS*_{P1} Tangential P1: 0.000401217*PS*_{P2} Tangential P2: 7.19026e-05

I know at this time how to convert some data from photomodeler to photoscan:

**Focal length***PS*_{fx} =

*PM*_{focal} x

*PM*_{wp} /

*PM*_{fw}*PS*_{fy} =

*PM*_{focal} x

*PM*_{hp} /

*PM*_{fh}**Principal point***PS*_{cx} =

*PM*_{ppx} x

*PM*_{wp} /

*PM*_{fw}*PS*_{cy} =

*PM*_{ppy} x

*PM*_{hp} /

*PM*_{fh}However, i wanted to know how to determine the skew (

*PS*_{skew}) parameter from photomodeler values and how to convert distortion.

Can you please help me ?

Thanks,

Julien