I'm looking at ways to visually watermark my photos. Adrian had suggested that I do that a while back, and I wasn't extremely excited about the idea at the time, but I was considering it today. I've seen several choices of how to do this visually:
- an extra layer on top of the image (optionally transparent)
- mat inside the image file. National Geographic does this (black band on the bottom). I worry that this will force larger file sizes, both because of the larger image resolution and the solid color mat's susceptibility to compresison artifacts.
- bump map the photo itself (watermark is clear and looks 3D).
Sans-serif fonts seem to be popular, perhaps because they look less busy than serif fonts.
There's also several points in the workflow that this watermark could be inserted into the image
- There's a GIMP watermark script (install by putting the script into a file $HOME/.gimp-2.2/watermark.scm and running Xtns:Script-Fu:Refresh Scripts) -- but it's not useful, for example, for exports from picasa. Another disadvantage to this script is that GIMP's kerning isn't very good.
- ImageMagick's composite:
composite -gravity SouthEast -geometry +100+100 watermarkfile.png orig.jpg new.jpgThis would necessarily reduce image quality
- Using something like PHP to serve the image and add the watermark. This would necessarily reduce image quality.
I ended up going with a GIMP script, because it seems the most flexible, and picasa exports don't have much control over JPEG encoding anyway, so if I had infinite time, I wouldn't use them. But I really didn't like the look of GIMP's text tool output so I wrote a new script that uses arbitrary images in the four corners.
Update (2010-11-14): A python version which works with gimp-2.6 is available at https://github.com/wtanaka/gimp-watermark. To install it:
- cp watermark-wtanaka.com.py $HOME/.gimp-2.6/plug-ins/
- chmod +x $HOME/.gimp-2.6/plug-ins/watermark-wtanaka.com.py