[GRASS-user] rectifying digital images

[Markus Neteler]

On Jan 5, 2008 8:24 AM, maning sambale <emmanuel.sambale at gmail.com> wrote:
...
> The photographs were taken along the flight line using a professional
> Kodak N14 digital SLR camera, which has a resolution of 14 megapixels.

You can figure out camera parameters with 'jhead':
http://www.sentex.net/~mwandel/jhead/

...
> What do I have now:
> over 800 photos
> GPS point location for each photo
> Quickbird image of the whole study area
>
> According to their report:
> There is difficulty in mosaicking the photographs. The
> original plan was to stitch the photographs together to create a
> composite image.

Indeed, AFAIK you really need to do bundle block adjustment.
The i.ortho.photo module is restriced to single frame rectification.

I once received a script collection to use Octave and GRASS
to perform bundle block adjustment but never got that working
(still have the code, we could contact the author).

Randomly seeking the internet, I found
http://www.ics.forth.gr/~lourakis/sba/
sba: A Generic Sparse Bundle Adjustment C/C++ Package Based
on the Levenberg-Marquardt Algorithm (GPL'ed)

> But the tilt in the photographs due to the movement of the aircraft
> requires that certain adjustments be made.

Definitely.

Markus
-- 
Open Source Geospatial Foundation
http://www.osgeo.org/
http://www.grassbook.org/