Ok, so you you have taken a bunch of photos with your new camera and what do you know, some of them are half decent. I use this after I have copied photo's I want to print or photo's that I am sending to flickr or deviant art to a seperate folder as it really adds a finishing touch, I copy them to a seperate location so I know exactly which ones I am printing/uploading and don't omit any.
Now you could easily do this in The Gimp, load each image and enlarge the canvas followed by a fill and then resave the image. This is linux though and we can do things a heap simpler than that!
First install Imagemagick:
sudo apt-get install imagemagick
Or install it via Synaptic or your package manager.
Then use this simple script,
be aware that you should operate on copies as this does overwrite the original, as noted above I only do this on photo's I have copied for printing/uploading.
for img in `ls *.jpg`
convert -bordercolor white -border 50x50 $img $img
Easiest to pop it all into a bash script, or just close it up separating the commands with semicolons into a one liner eg.
for img in `ls *.jpg` ; do ; convert -bordercolor white -border 50x50 $img $img ; done
If your camera uses a different extension then adjust the .jpg accordingly.
Adjust "50x50" to whatever you feel adds a nicely sized border, and feel free to change the border colour (black for instance). If you want to get creative stack up the converts to add a thin black border before a larger white border or whatever you fancy.