[libextractor] Re: exif thumbnail not found allthough it is present in the file

[Christian Grothoff]

Zitat von Sergey 'Jin' Bostandzhyan <address@hidden>:
> Hi,
>
> I have jpeg images with exif information and exif thumbnails,
> I was trying to extract the thumbnail with the help of libextractor 0.5.2
> using the following function:
>
> EXTRACTOR_extractLast(EXTRACTOR_THUMBNAIL_DATA, keywords);
>
> Unfortunately I get NULL back, also, the command line tool extract also does
> not give any information regarding binary thumbnail data. The images I am
> using
> definetely have exif thumbnails - I can extract them with the libexif
> library.
>
> Do you have any ideas why this is failing? Other information, such as
> camera model etc. is working, so the exiv2 plugin is functional.
>
> By the way, it would also be nice to have a keyword to retrieve the thumbnail
> resolution in pixels, if I am not mistaken exiv2 is offering a keyword for
> it.

The existing exiv2 plugin does not really extract the thumbnail information
(maybe a limitation of the plugin code itself).  LE supports thumbnails, but
only by computing them from scratch (not by reading exiv2 data).  For that,
load the "thumbnail" plugin (and you will get thumbnails even without exiv2
data).

I can see that it would be nice to get the thumbnail (and possibly thumbnail
resolution) from exiv2 directly, but I won't have time to do this myself
anytime soon :-).

Best regards

Christian
p.s.: I think these kinds of questions should go to the LE mailinglist :-).
Also gives you a better chance of finding someone who would actually
hack this up :-).