Tagging Photographs

I've been looking at metadata in Photographs. I started with this piece. Had to update it to work with more recent version of Jena, but it works. However it omits most of my Canon makertags. Then Sean found exiftool which is a really professional bit of software. Does way more than I will ever need. So I started to stitch together a chain of apps. Pull the existing Exif data, wrap it to make it N3 using a bit of Python, then cwm to get it into XML/RDF notation. Then finally I can use jpegrdf to stuff it back into the image, in the comment field. I extended it this morning to work with a whole directory of jpegs. Except. I was nattering with Sean yesterday, about storage and backup and stuff. Then we started talking about actually using the software, now I have it. My initial thoughts were to add the sort of comment that you'd find under a photograph. Aunty Jean at Mablethorpe, 1922, etc. dc:title, dc:description, perhaps even geo:lat and geo:long. Seans comments hurt, as in the truth hurts. Going for longevity, his suggestion was to add a plain text file in the directory with the comments I wanted to add. If exif 2.2 has developed into exif 10.6 by the time the images are seen, then there is a fair chance that the image metadata will have been lost. The chances of losing the text file? Nil. Or at least if it's lost, so will the images. I'm still trying to refute his arguments. I took one step by stating that XML is as good as text. Perhaps pull the rdf and save it in the same directory? Then I can keep valid RDF, yet avoid the trap of burying it in a binary format? The N3 isn't far from readable anyway, despite comments from Jeni.

exif:data a exif:dataset;
dc:date "2007-08-17";
#  ExifTool -
exif:ExifToolVersion "6.94";
#  File -
exif:FileName "058.Original.jpg";
exif:Directory ".";
exif:FileSize "1065 kB";
exif:FileModifyDate "2007:08:19 08:38:34";
exif:FileType "JPEG";
exif:MIMEType "image/jpeg";

etc

The information is there to resolve the association with the file. Then I can add the geo stuff, titles etc as needed. I think you're right Sean.

First time I've knitted together so many bits of programs though. That was quite interesting. I've always been impressed by shell scripting. Still makes me smile when I think back to dos scripts. This was a case very much aligned to the Unix philosophy, take a tool which is good at one thing, and pipe them together to perform larger tasks.

exiftool  -a -u -g1 -s -t $1  >tmp.tmp
if [ $? -ne 0 ]
   then
    echo Error reported by exiftool, quitting
    exit 2
fi



python /files/python/exifRDF.py -i tmp.tmp -o tmp.n3
if [ $? -ne 0 ]
   then
    echo Error reported by exifRDF.py, quitting
    exit 2
fi

cwm --n3 tmp.n3 --rdf >tmp.rdf
if [ $? -ne 0 ]
   then
    echo Error reported by cwm, quitting
    exit 2
fi

cd=/apps/jpegrdf
CP=$cd/jpegrdf.jar:$cd:$cd/commons-logging-1.1.jar:  \
$cd/icu4j_3_8_d01.jar:$cd/iri.jar:$cd/jena.jar: \
$cd/xercesImpl.jar:$cd/xerces.jar

java -cp $CP com.nwalsh.jpegrdf.JpegRDF -rdf tmp.rdf $1

I like the idea of mixing Perl Python and Java too!