1 files changed, 125 insertions, 0 deletions

diff --git a/thumbnailer.py b/thumbnailer.py
new file mode 100755
index 0000000..cebbf72
--- /dev/null
+++ b/thumbnailer.py
@@ -0,0 +1,125 @@
+#!/usr/bin/env python2.6
+
+import hmac
+import urllib2
+import urlparse
+from cStringIO import StringIO
+
+from PIL import Image, ImageOps
+from PIL.ImageFileIO import ImageFileIO
+
+
+def crop_image(img, width, height):
+    src_width, src_height = img.size
+    src_ratio = float(src_width) / float(src_height)
+    dst_width, dst_height = int(width), int(height)
+    dst_ratio = float(dst_width) / float(dst_height)
+
+    if dst_ratio < src_ratio:
+        crop_height = src_height
+        crop_width = crop_height * dst_ratio
+        x_offset = float(src_width - crop_width) / 2
+        y_offset = 0
+    else:
+        crop_width = src_width
+        crop_height = crop_width / dst_ratio
+        x_offset = 0
+        y_offset = float(src_height - crop_height) / 3
+
+    img = img.crop((x_offset, y_offset, x_offset+int(crop_width), y_offset+int(crop_height)))
+
+    return img
+
+
+def calculate_size(img, long_side):
+    width, height = img.size
+    width, height = float(width), float(height)
+
+    if height > width:
+        width = (width / height) * long_side
+        height = long_side
+    else:
+        height = (height / width) * long_side
+        width = long_side
+
+    return width, height
+
+
+def load_remote_image(url):
+    return Image.open(ImageFileIO(urllib2.urlopen(url)))
+
+
+def create_thumbnail(img, long_side):
+    width, height = calculate_size(img, int(long_side))
+    img.thumbnail((width, height), Image.ANTIALIAS)
+    return img
+
+
+def desaturate_image(img):
+    img = ImageOps.grayscale(img)
+    return img
+
+
+KEY = ""
+
+OPERATIONS = {
+    "thumb": (create_thumbnail, 1),
+    "crop": (crop_image, 2),
+    "desaturate": (desaturate_image, 0),
+}
+
+def generate_sig(query):
+    clean = ["{0}{1}".format(k,v) for k, v in query if k != "sig"]
+    return hmac.new(KEY, "".join(clean)).hexdigest()
+
+
+def thumbnailer_app(environ, start_response):
+    to_do = []
+    qs = []
+    for tup in urlparse.parse_qsl(environ.get('QUERY_STRING', '')):
+        if tup[0] == "sig":
+            sig = tup[1]
+        else:
+            qs.append(tup)
+
+    # Validate
+    if generate_sig(qs) != sig:
+        start_response('401 Forbidden', [('Content-Type', 'text/plain')])
+        return ["You may not use the thumbnailer for that site."]
+
+    need_values = 0
+    for key, value in qs:
+        if need_values > 0:
+            to_do[-1].append(value)
+            need_values -= 1
+            continue
+
+        if key == "image":
+            path = value
+        elif key == "op":
+            op, args = OPERATIONS[value]
+            need_values = args
+            to_do.append([op])
+
+    # Start the web response
+    start_response('200 OK', [('Content-Type', 'image/jpeg')])
+
+    img = load_remote_image(path)
+
+    for action in to_do:
+        func = action.pop(0)
+        img = func(img, *action)
+
+    return img.tostring('jpeg', img.mode)
+
+
+if __name__ == "__main__":
+    import sys
+
+    if len(sys.argv) == 2:
+        qs = urlparse.parse_qsl(urlparse.urlparse(sys.argv[-1]).query)
+        print "{0}&sig={1}".format(sys.argv[-1], generate_sig(qs))
+        sys.exit(0)
+
+    from flup.server.fcgi_fork import WSGIServer
+    WSGIServer(thumbnailer_app, debug=True, maxSpare=1).run()