PTlens database updates?

[Davide Capodaglio]

Hi all, I have a Canon IXUS 850IS and I would like to use hugin and
fulla tools to correct my photos deformations.
However my camera is present in the official PTlens binary database,
but not in the public old one in text format used by fulla...
Is there any chance that latest cameras will be included in the open
database?
If not how can I determine my own distortion parameters by myself? Is
this possible?

Thanks
Davide

[Bruno Postle]

On Fri 21-Nov-2008 at 13:15 -0800, Davide Capodaglio wrote:
>
>Is there any chance that latest cameras will be included in the open
>database?

Probably, but I have no idea if anyone is collecting the data at the
moment. Development of the lens database has moved to lensfun:

http://lensfun.berlios.de/

>If not how can I determine my own distortion parameters by myself? Is
>this possible?

The easiest way is to simply stitch a panorama in hugin and read the
optimised values from the 'Camera and Lens' tab.

--
Bruno

[Oskar Sander]

Seems like someone added a new lens to the DB yesterday, so Lensfun seems to be in some use still.    What would it take to integrate it w hugin?


There was an interesting comment on the lensfun site.   Photozone-de publicize distortion parameters with their lens reviews, this would be useful if a transformation to the current panotools model could be determined,  see [1].  

But of course the highest priority should be to find someone who can explain the transformation between the new lens calibration tool, and the current panotools model.

BTW, what quality images are needed to determine parameters reliably, would something like this [2] suffice quality wise? Do you need to have a stack of similar photos to get a reliable figure?


[1] http://www.photozone.de/images/8Reviews/lenses/pentax_18250_3563/18mm_distortion.png
[2] http://picasaweb.google.se/oskar.sander/LensCalibrationTargets#5416313840639142754

2008/11/24 Bruno Postle <br...@postle.net>

--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups "hugin and other free panoramic software" group.
A list of frequently asked questions is available at: http://wiki.panotools.org/Hugin_FAQ
To post to this group, send email to hugi...@googlegroups.com
To unsubscribe from this group, send email to hugin-ptx-...@googlegroups.com
For more options, visit this group at http://groups.google.com/group/hugin-ptx
-~----------~----~----~----~------~----~------~--~---

--
/O

[John McAllister]

The lens distortion parameters of any particular lens @ focal length x are also dependent on the camera sensor dimensions.

Lists of distortion parameters are derived from specific lens/sensor combinations (without specifying the sensor characteristics).

 

I would strongly suggest that photographers determine these parameters themselves, for their own particular setup.

 

A simple approach is to set up a single row of suitable 50% overlapping shots, CP and stitch then save the lens info.

The lens info file is simple text that can be easily edited, to add x and y shifts, for example.

 

Take especial care to ensure that the camera is mounted very close to a right angel to the axis of rotation and that parallax is eliminated beforehand.

 

Work progressively; start by working out a reasonable FoV, from a prior stitch, to use as a starting value, but allow it to optimise.

After the distortion parameters have been determined, work on the x and y shifts; first one then the other.

 

Happy New Year folks.

http://panavista.eu/