Structure of PhotoScan XML format?

[kwarfvinge]

Hi,

I am currently evaluating PhotoScan Pro to see if it can replace our current photogrammetry software. I have a two camera setup with known intrinsic and extrinsic camera parameters obtained by our current software. I would like to import this calibration into PhotoScan Pro as an XML file (using Tools/Import/Import Cameras), but I don't know the exact structure of the PhotoScan XML format. I have tried constructing XMLs from bits of information I've found on this forum, but I only get an "Can't import cameras" error message. If I didn't have an evaluation copy I could of course have made a test calibration and exported that to XML to get a template, but evaluation does not allow saving of files. So, does anyone know the exact XML structure needed?

Also: it seems that the transformation is now expressed as a 4x4 matrix. Is this a [R t; 0 0 0 1] matrix (where R is a 3x3 rotation matrix, and t a 3x1 translation vector), or how do you otherwise get this from R and t?

Thanks in advance!
/Kajsa

[Alexey Pasumansky]

Hello Kajsa,

You can align two cameras and then use Export Cameras option to check the format. Please note that correct camera labeling in the .xml file is important.

t - is a translation vector, t = (x, y, z)
Camera rotation matrix can be calculated is rotational angles around coordinate axis are known.

What kind of information do you have for the camera positions and calibration?

[kwarfvinge]

Hi,
That was a very quick reply! However, as I am currently only evaluating the software, I can't Export Cameras ("Saving data is disabled in the demo mode").

The parameters I have are:

• focal length (same for x & y)
• principal points (x & y)
• 1st and 2nd order radial distortion
• translation vector (x, y, z)
• rotation matrix built like: Rz*Ry*Rx, where Rx, Ry and Rz are as defined in http://en.wikipedia.org/wiki/Rotation_matrix#Basic_rotations

I tried to label the camera with the name of the corresponding image, but I still can't read the file.

/Kajsa

[Alexey Pasumansky]

Hello Kajsa,

You can request Trial version of PhotoScan Pro through the corresponding web-form:
http://www.agisoft.ru/products/photoscan/professional/trial/

Also you can send us the calibration, position information with the sample photos to support@agisoft.ru, in case you still got problems with the .xml format.