According to Google, this should do the trick
perl -p -i -e 's/\[\[Image$(.+?)$\]\]/\{\{thumbnail$$1$\}\}/g' filename.txt

(note that it replaces [[Image...]] with {{thumbnail...}} in the file without creating a backup)).

/Jens E

2016-02-19 21:00 GMT+01:00 Holger Freyther <holger@freyther.de>:

> On 19 Feb 2016, at 08:09, Holger Freyther <holger@freyther.de> wrote:
>
>
> The wiki conversion is not that great. We really have to do some work in post processing and making sure that all content has been migrated. E.g. "Software/Overview" and "SoftwareOverview" seem to confuse the importer:
>
> http://projects.osmocom.org/projects/baseband/wiki/SoftwareOverview vs. http://bb.osmocom.org/trac/wiki/Software/Overview vs. http://bb.osmocom.org/trac/wiki/SoftwareOverview

I am fixing this but if somebody wants to help with some code/regexp it would be nice too.

In trac we have:

[[Image(motorola_filter_replacement_step_1_low.jpg, 250px)]]

For redmine we need:

{{thumbnail(motorola_filter_replacement_step_1_low.jpg, size=250)}}

Anyone wants to try his luck with a regexp to do this automatically? Or a bit of ruby code to split and manipulate if it is matching [[Image?