I typically build automatic resizing into any django models that use ImageField by overriding the save function like so:
def save(self):
super(GalleryImage, self).save() # Call the "real" save() method
if self.image:
# now change the size of the image
path = settings.MEDIA_ROOT + self.image
img1 = PIL.open(path)
img2 = PIL.open(path)
img2.save(self.get_thumbnail_path())
size = 600,600
img1.thumbnail(size, PIL.ANTIALIAS)
img1.save(path)
# create the thumbnail
size = 150, 150
img2.thumbnail(size, PIL.ANTIALIAS)
img2.save(self.get_thumbnail_path())
def get_thumbnail_path(self):
path = settings.MEDIA_ROOT + self.image
return self.convert_path_to_thumbnail(path)
def get_thumbnail_url(self):
path = self.get_image_url()
return self.convert_path_to_thumbnail(path)
def convert_path_to_thumbnail(self, path):
basedir = os.path.dirname(path) + '/'
base, ext = os.path.splitext(os.path.basename(path))
# make thumbnail filename
th_name = base + "_tn"
th_name += ext
return urlparse.urljoin(basedir, th_name)
This ensures that all my images conform to the sizes I need. However, even if the server is automatically resizing the images for me, I don’t want to spend hours uploading huge images only to have them resized. It’s just a waste of bandwidth and time. So, I’ve written a quick python script that resizes all the images in a given directory and places the copies in a new directory called resized:
#! /usr/bin/env python
"""
What:
Resize all the jpg images in a directory
All images will be placed inside a directory called "resized"
This directory must exist
Usage: ./resize.py
"""
import PIL.Image as PIL
import re, os, sys, urlparse
SIZE = 600,600
JPG = re.compile(".*\.(jpg|jpeg)", re.IGNORECASE)
def get_new_path(path):
basedir = os.path.dirname(path) + '/resized/'
base, ext = os.path.splitext(os.path.basename(path))
file = base + ext
return urlparse.urljoin(basedir, file)
try:
image_dir = sys.argv[1]
except:
print "You must specify a directory"
exit(0)
files = os.listdir(image_dir)
for file in files:
if JPG.match(file):
f = image_dir.rstrip("/") + "/" + file
print f
img = PIL.open(f)
img.thumbnail(SIZE, PIL.ANTIALIAS)
img.save(get_new_path(f))
