Hugin should support the lensfun lens database

[Bruno Postle]

lensfun is a database and library that allows applications to access and save lens correction settings: http://lensfun.berlios.de/

lensfun was in part designed for Hugin as a replacement for the existing .ini lens saving system, it is mature and has been adopted by ufraw and rawstudio, it is about time that Hugin started using it.

[tmodes (tmodes)]

I had a short look on lensfun. Some comments from me:

1.) Lensfun stores only a very rough lens types:
From the doc: <type>string</type> Lens type. This is one of: "rectilinear", "fisheye", "panoramic", "equirectangular".
But hugin has e.g. a finer grain for fisheye lenses (full frame fisheye, circular fisheye, thoby, orthographic?) So how do we handle this cases?
2.) For fisheye lenses the crop rectangle/circle is not stored in the database. But I think this is needed for hugin needs.
3.) Lensfuns does currently not support a native windows compile. It supports only cross compile, that means you need a linux system to generate the lib for the windows version. We need to find a solution for this.

[tmodes (tmodes)]

Short update:
I patched the lensfun library to fix the mentioned issues. The patches were uploaded to the lensfun patch tracker.

[Bruno Postle (brunopostle)]

Links to the lensfun patches for future reference:

http://developer.berlios.de/patch/?func=detailpatch&patch_id=3227&group_id=9034
http://developer.berlios.de/patch/?func=detailpatch&patch_id=3228&group_id=9034
http://developer.berlios.de/patch/?func=detailpatch&patch_id=3229&group_id=9034

[tmodes (tmodes)]

Implemented in changeset f09bd1ceb2a8

[Bruno Postle (brunopostle)]

Thanks, links, builds and runs on fedora f15.

f15 has an old version of lensfun (0.2.5), so this report is probably not very useful:

I have a compact Panasonic Lumix LX3, which is in the database, the lens entry looks like this:

        <maker>Leica</maker>
        <model>Standard</model>
        <mount>panasonicLX3</mount>
              ...

I can only get a search match in Hugin with the string 'standard', unfortunately there are 86 lenses called 'standard' in the database, so it isn't practical to select the right one.

[Bruno Postle (brunopostle)]

Hi Thomas, current 6916593231ee works with the compact LX3 camera. Loading the lens using lensfun adds plausible lens distortion parameters, but doesn't alter the field-of-view - Looking at the lensfun patch, this is a limitation of the older lensfun I have here.

A minor thing: in the 'load lens from database' window, the values for focal length and aperture are rounded to the nearest whole number, these would both be better as "focal length: 5.1mm, Aperture f/4.0" rather than "focal length: 5mm, Aperture f/4".

BTW it builds fine on fedora f15, f16, f17 & f18, all with both i386 and x86_64.

[tmodes (tmodes)]

Hi Bruno,

I committed a change to display the focal length with one decimal place. The aperture was already displayed with one decimal place. When the decimal place contains only zero, it is not displayed - so no rounding.

Also the writing to the database was improved for compact camera. I hope, this works correctly.