How to use PIL to resize and apply rotation EXIF information to the file?

Question

I am trying to use Python to resize picture. With my camera, files are all written is landscape way.

The exif information handle a tag to ask the image viewer to rotate in a way or another. Since most of the browser doesn't understand this information, I want to rotate the image using this EXIF information and keeping every other EXIF information.

Do you know how I can do that using Python ?

Reading the EXIF.py source code, I found something like that :

0x0112: ('Orientation',          {1: 'Horizontal (normal)',           2: 'Mirrored horizontal',           3: 'Rotated 180',           4: 'Mirrored vertical',           5: 'Mirrored horizontal then rotated 90 CCW',           6: 'Rotated 90 CW',           7: 'Mirrored horizontal then rotated 90 CW',           8: 'Rotated 90 CCW'}) 

How can I use this information and PIL to apply it ?

Answer 1

I finally used pyexiv2, but it is a bit tricky to install on other platforms than GNU.

#!/usr/bin/python # -*- coding: utf-8 -*- # Copyright (C) 2008-2009 Rémy HUBSCHER <[email protected]> - http://www.trunat.fr/portfolio/python.html  # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; either version 2 of the License, or # (at your option) any later version.  # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details.  # You should have received a copy of the GNU General Public License along # with this program; if not, write to the Free Software Foundation, Inc., # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.  # Using : #   - Python Imaging Library PIL    http://www.pythonware.com/products/pil/index.htm #   - pyexiv2                       http://tilloy.net/dev/pyexiv2/  ### # What is doing this script ? # #  1. Take a directory of picture from a Reflex Camera (Nikon D90 for example) #  2. Use the EXIF Orientation information to turn the image #  3. Remove the thumbnail from the EXIF Information #  4. Create 2 image one maxi map in 600x600, one mini map in 200x200 #  5. Add a comment with the name of the Author and his Website #  6. Copy the EXIF information to the maxi and mini image #  7. Name the image files with a meanful name (Date of picture)  import os, sys try:     import Image except:     print "To use this program, you need to install Python Imaging Library - http://www.pythonware.com/products/pil/"     sys.exit(1)  try:     import pyexiv2 except:     print "To use this program, you need to install pyexiv2 - http://tilloy.net/dev/pyexiv2/"     sys.exit(1)  ############# Configuration ############## size_mini = 200, 200 size_maxi = 1024, 1024  # Information about the Photograph should be in ASCII COPYRIGHT="Remy Hubscher - http://www.trunat.fr/" ARTIST="Remy Hubscher" ##########################################  def listJPEG(directory):     "Retourn a list of the JPEG files in the directory"     fileList = [os.path.normcase(f) for f in os.listdir(directory)]     fileList = [f for f in fileList if os.path.splitext(f)[1]  in ('.jpg', '.JPG')]     fileList.sort()     return fileList  def _mkdir(newdir):     """     works the way a good mkdir should :)       - already exists, silently complete       - regular file in the way, raise an exception       - parent directory(ies) does not exist, make them as well     """     if os.path.isdir(newdir):         pass     elif os.path.isfile(newdir):         raise OSError("a file with the same name as the desired " \                       "dir, '%s', already exists." % newdir)     else:         head, tail = os.path.split(newdir)         if head and not os.path.isdir(head):             _mkdir(head)         if tail:             os.mkdir(newdir)  if len(sys.argv) < 3:     print "USAGE : python %s indir outdir [comment]" % sys.argv[0]     exit  indir  = sys.argv[1] outdir = sys.argv[2]  if len(sys.argv) == 4:     comment = sys.argv[1] else:     comment = COPYRIGHT  agrandie = os.path.join(outdir, 'agrandie') miniature = os.path.join(outdir, 'miniature')  print agrandie, miniature  _mkdir(agrandie) _mkdir(miniature)  for infile in listJPEG(indir):     mini  = os.path.join(miniature, infile)     grand = os.path.join(agrandie, infile)     file_path = os.path.join(indir, infile)      image = pyexiv2.Image(file_path)     image.readMetadata()      # We clean the file and add some information     image.deleteThumbnail()      image['Exif.Image.Artist'] = ARTIST     image['Exif.Image.Copyright'] = COPYRIGHT      image.setComment(comment)      # I prefer not to modify the input file     # image.writeMetadata()      # We look for a meanful name     if 'Exif.Image.DateTime' in image.exifKeys():         filename = image['Exif.Image.DateTime'].strftime('%Y-%m-%d_%H-%M-%S.jpg')         mini  = os.path.join(miniature, filename)         grand = os.path.join(agrandie, filename)     else:         # If no exif information, leave the old name         mini  = os.path.join(miniature, infile)         grand = os.path.join(agrandie, infile)      # We create the thumbnail     #try:     im = Image.open(file_path)     im.thumbnail(size_maxi, Image.ANTIALIAS)      # We rotate regarding to the EXIF orientation information     if 'Exif.Image.Orientation' in image.exifKeys():         orientation = image['Exif.Image.Orientation']         if orientation == 1:             # Nothing             mirror = im.copy()         elif orientation == 2:             # Vertical Mirror             mirror = im.transpose(Image.FLIP_LEFT_RIGHT)         elif orientation == 3:             # Rotation 180°             mirror = im.transpose(Image.ROTATE_180)         elif orientation == 4:             # Horizontal Mirror             mirror = im.transpose(Image.FLIP_TOP_BOTTOM)         elif orientation == 5:             # Horizontal Mirror + Rotation 90° CCW             mirror = im.transpose(Image.FLIP_TOP_BOTTOM).transpose(Image.ROTATE_90)         elif orientation == 6:             # Rotation 270°             mirror = im.transpose(Image.ROTATE_270)         elif orientation == 7:             # Horizontal Mirror + Rotation 270°             mirror = im.transpose(Image.FLIP_TOP_BOTTOM).transpose(Image.ROTATE_270)         elif orientation == 8:             # Rotation 90°             mirror = im.transpose(Image.ROTATE_90)          # No more Orientation information         image['Exif.Image.Orientation'] = 1     else:         # No EXIF information, the user has to do it         mirror = im.copy()      mirror.save(grand, "JPEG", quality=85)     img_grand = pyexiv2.Image(grand)     img_grand.readMetadata()     image.copyMetadataTo(img_grand)     img_grand.writeMetadata()     print grand      mirror.thumbnail(size_mini, Image.ANTIALIAS)     mirror.save(mini, "JPEG", quality=85)     img_mini = pyexiv2.Image(mini)     img_mini.readMetadata()     image.copyMetadataTo(img_mini)     img_mini.writeMetadata()     print mini      print 

If you see something that could be improved (except the fact that it is still for Python 2.5) then please let me know.

Answer 2

Although PIL can read EXIF metadata, it doesn't have the ability to change it and write it back to an image file.

A better choice is the pyexiv2 library. With this library it's quite simple flip the photo's orientation. Here's an example:

import sys import pyexiv2  image = pyexiv2.Image(sys.argv[1]) image.readMetadata()  image['Exif.Image.Orientation'] = 6 image.writeMetadata() 

This sets the orientation to 6, corresponding to "Rotated 90 CW".