Decided that I want to timestamp my photo collection with the date from the exif data. Many digicams have an option to do this - unfortunately, my Panasonic DMC-LZ8 doesn't seem to do this. I knew imagemagick would do the trick, but thought it would be a good time to play around with PIL and python.
Here's my PIL effort - functional, but one that came with quite some amount of googling and trying to make sense of the PIL documentation which is inadequate at best.
[sourcecode language="python"]
from PIL import Image
from PIL import ImageFont, ImageDraw
from PIL.ExifTags import TAGS
from os.path import basename, dirname,join
import logging
import sys
import datetime
import time
# Important: I set out to write the image annotation in PIL - there's one serious drawback though. When saving
# the image, the exif data is'nt preserved.
logging.basicConfig(level=logging.DEBUG,
format='%(asctime)s %(levelname)s %(message)s')
logger = logging.getLogger()
logger.level = logging.DEBUG
def readExif(image):
info = image._getexif()
ret ={}
for tag,value in info.items():
ret[TAGS.get(tag,tag)] = value
dt = datetime.datetime (*time.strptime (ret['DateTime'],"%Y:%m:%d %H:%M:%S")[0:6])
ret['DateTime'] = dt
return ret
def annotateImage (file):
i = Image.open(file)
font = ImageFont.truetype("/usr/share/fonts/truetype/ttf-dejavu/DejaVuSans-Bold.ttf", 36)
exif = readExif(i)
draw = ImageDraw.Draw(i)
width, height = i.size
draw.text((width * 0.7, height - 100),exif['DateTime'].strftime("%a %d-%b-%Y %l:%M %p"), font=font, fill='orange')
outfile = join(dirname(file), "Ann_" + basename(file))
i.save (outfile, quality=98)
logger.debug (outfile + " saved")
if __name__== "__main__":
logger.debug ("getting exif for " + sys.argv[1])
for file in sys.argv[1:]:
logger.debug ("Annotating " + file)
annotateImage(file)
[/sourcecode]
Unfortunately, PIL has a fatal flaw - you can annotate the image and save it - but then the saved image doesn't retain the original image's exif metadata. I also tried the exiv2 library, but couldnt figure out a way to load the image, annotate it and then copy over the metadata. Googling around didn't turn up any intersting solutions - so if any of you have any ideas, please share.
Meanwhile, as I was getting tired of coaxing PIL to do what I want, I just wrote a a little bash script to do the same in imagemagick. Its as painless as it can be, comes with excellent documentation, hardly any gotchas, a world of options in case you feel creative and the job gets done in 10 mins. Here's the bash script below.
#! /bin/bash
# script adds a black 18px bottom border to the pic with the Exif datetime tag
# no safety checks :). Original pics are left untouched.
while [ "x$*" != "x" ]
do
file=$1;
shift;
outfile="$(dirname "$file")/Ann_$(basename "$file")"
echo $outfile
echo $file
date=$(identify -verbose "$file" | grep 'DateTime:'| sed 's/ Exif:DateTime: //;s/:/-/;s/:/-/')
date="$(date -d "$date" +"%a %d-%b-%Y %l:%M %p")"
convert "$file" -size 1x18 xc:Black -fill White -background Black -append -gravity Southeast -draw "text 0,0 '$date'" "$outfile"
done
Overall, the experience left me dissappointed and dissatisfied with PIL.