Python: Remove Exif info from images

问题:

In order to reduce the size of images to be used in a website, I reduced the quality to 80-85%. This decreases the image size quite a bit, up to an extent.

To reduce the size further without compromising the quality, my friend pointed out that raw images from cameras have a lot of metadata called Exif info. Since there is no need to retain this Exif info for images in a website, we can remove it. This will further reduce the size by 3-10 kB.

But I'm not able to find an appropriate library to do this in my Python code. I have browsed through related questions and tried out some of the methods:

Original image: http://mdb.ibcdn.com/8snmhp4sjd75vdr27gbadolc003i.jpg

1. Mogrify

   /usr/local/bin/mogrify -strip filename
   

   Result: http://s23.postimg.org/aeaw5x7ez/8snmhp4sjd75vdr27gbadolc003i_mogrify.jpg This method reduces the size from 105 kB to 99.6 kB, but also changed the color quality.

2. Exif-tool

   exiftool -all= filename
   

   Result: http://s22.postimg.org/aiq99o775/8snmhp4sjd75vdr27gbadolc003i_exiftool.jpg This method reduces the size from 105 kB to 72.7 kB, but also changed the color quality.

3. This answer explains in detail how to manipulate the Exif info, but how do I use it to remove the info?

Can anyone please help me remove all the extra metadata without changing the colours, dimensions, and other properties of an image?

回答1:

You can try loading the image with the Python Image Lirbary (PIL) and then save it again to a different file. That should remove the meta data.

回答2:

from PIL import Image

image_file = open('image_file.jpeg')
image = Image.open(image_file)

# next 3 lines strip exif
data = list(image.getdata())
image_without_exif = Image.new(image.mode, image.size)
image_without_exif.putdata(data)

image_without_exif.save('image_file_without_exif.jpeg')

回答3:

For me, gexiv2 works fine:

#!/usr/bin/python3

from gi.repository import GExiv2

exif = GExiv2.Metadata('8snmhp4sjd75vdr27gbadolc003i.jpg')
exif.clear_exif()
exif.clear_xmp()
exif.save_file()

See also Exif manipulation library for python, which you linked, but didn't read all answers ;)

回答4:

You don't even need to do the extra steps @user2141737 suggested. Just opening it up with PIL and saving it again seems to do the trick just fine:

from PIL import Image
image = Image.open('path/to/image')
image.save('new/path/' + file_name)