Upload resized image to S3

Question

I'm trying to upload resized image to S3:

fp = urllib.urlopen('http:/example.com/test.png')
img = cStringIO.StringIO(fp.read())

im = Image.open(img)
im2 = im.resize((500, 100), Image.NEAREST)  
AK = 'xx' # Access Key ID 
SK = 'xx' # Secret Access Key

conn = S3Connection(AK,SK) 
b = conn.get_bucket('example')
k = Key(b)
k.key = 'example.png'
k.set_contents_from_filename(im2)

but I get an error:

 in set_contents_from_filename
    fp = open(filename, 'rb')
TypeError: coercing to Unicode: need string or buffer, instance found

Answer 1

You need to convert your output image into a set of bytes before you can upload to s3. You can either write the image to a file then upload the file, or you can use a cStringIO object to avoid writing to disk as I've done here:

import boto
import cStringIO
import urllib
import Image

#Retrieve our source image from a URL
fp = urllib.urlopen('http://example.com/test.png')

#Load the URL data into an image
img = cStringIO.StringIO(fp.read())
im = Image.open(img)

#Resize the image
im2 = im.resize((500, 100), Image.NEAREST)  

#NOTE, we're saving the image into a cStringIO object to avoid writing to disk
out_im2 = cStringIO.StringIO()
#You MUST specify the file type because there is no file name to discern it from
im2.save(out_im2, 'PNG')

#Now we connect to our s3 bucket and upload from memory
#credentials stored in environment AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY
conn = boto.connect_s3()

#Connect to bucket and create key
b = conn.get_bucket('example')
k = b.new_key('example.png')

#Note we're setting contents from the in-memory string provided by cStringIO
k.set_contents_from_string(out_im2.getvalue())