Merge pull request #17 from HackRU/transparent_qr_background

Transparent qr background

qr_script.py

@@ -0,0 +1,23 @@
+#!/usr/bin/env python
+# run with `chromium $(python qr_script.py test@example.com)`
+
+import io
+import qrcode
+import PIL
+import base64
+import sys
+
+def email2qr(email):
+    #construct the QR code
+    img = qrcode.make(email)
+    #save as a byte array
+    byteArr = io.BytesIO()
+    img.save(byteArr, format='PNG')
+    byteImg = byteArr.getvalue()
+    #then read and encode.
+    encodedImg = base64.standard_b64encode(byteImg)
+    return 'data:image/png;base64,' + encodedImg.decode()
+
+if __name__ == '__main__':
+    email = sys.argv[1] if len(sys.argv) >= 2 else 'test@example.com'
+    print(email2qr(email))

qr_script.sh

@@ -0,0 +1,8 @@
+#!/usr/bin/env bash
+# run with `chromium $(./qr_script.sh test@example.com)`
+email='test@example.com'
+if test $# -ge 1
+then
+	email=$1
+fi
+curl -H "content-type: application/json" -d "{\"email\": \"$email\", \"color\": [0,0,0], \"background\": [255,255,255]}" https://m7cwj1fy7c.execute-api.us-west-2.amazonaws.com/test/qr | grep -o 'data.*",' | sed 's/..$//'

qru.py

@@ -9,14 +9,22 @@ def email2qr(event, context):
     The event is expected to have an email
     and optionally a color and a background (color)
     (both being 3-tuples of RGB values).
+    It also takes optional parameters fgOpacity and bgOpacity,
+    which set the foreground and background opacity, respectively.
+    It can also take a boolean transparentBackground which, if true,
+    overrides bgOpacity and makes the background fully transparent.
     Provided this, the function returns the base-64
     encoded QR code for the email in color passed in
     as 'color' and background color passed as 'background'.
     """
 
-    #We default to a black on white QR.
+    # We default to a black on white QR
+    # and full opacity in both the foreground and background.
     color = event.get('color', [0x0,0x0,0x0])
     background = event.get('background', [0xff,0xff,0xff])
+    fgOpacity = event.get('fgOpacity', 0xff)
+    bgOpacity = event.get('bgOpacity', 0xff)
+    bgOpacity = 0x0 if event.get('transparentBackground') else bgOpacity
 
     #email must be provided
     if 'email' not in event:
@@ -29,8 +37,9 @@ def email2qr(event, context):
     r = pilImg.point(lambda x: color[0] if x == 0 else background[0], mode='L')
     g = pilImg.point(lambda x: color[1] if x == 0 else background[1], mode='L')
     b = pilImg.point(lambda x: color[2] if x == 0 else background[2], mode='L')
+    a = pilImg.point(lambda x: fgOpacity if x == 0 else bgOpacity, mode='L')
     #we merge the RGB processed as above.
-    img = PIL.Image.merge('RGB', (r,g,b))
+    img = PIL.Image.merge('RGBA', (r,g,b,a))
     #save as a byte array
     byteArr = io.BytesIO()
     img.save(byteArr, format='PNG')