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
/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.
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.
Can anyone please help me remove all the extra metadata without changing the colours, dimensions, and other properties of an image?
from PIL import Image
image = Image.open('image_file.jpeg')
# 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')