diff --git a/.gitignore b/.gitignore
index 9f33c8d..df06075 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
-lifxlan/
\ No newline at end of file
+lifxlan/
+monitor-1.png
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..88537d6
--- /dev/null
+++ b/README.md
@@ -0,0 +1,10 @@
+# Screenlifx
+Set LIFX color with the average screen color
+
+## Open
+```
+python3 screenlifx.py
+```
+
+## Close
+Ctrl + C in Python3 interpreter
diff --git a/requirements.txt b/requirements.txt
new file mode 100644
index 0000000..8bdd1cb
--- /dev/null
+++ b/requirements.txt
@@ -0,0 +1,3 @@
+lifxlan==1.2.5
+mss==4.0.3
+Pillow==6.1.0
diff --git a/screenlifx.py b/screenlifx.py
old mode 100644
new mode 100755
index b9995ec..369cf49
--- a/screenlifx.py
+++ b/screenlifx.py
@@ -1,13 +1,13 @@
-#! python2.7-32
+#!/usr/bin/env python3
 
 # some quick & dirty code to set LIFX color with the average
 # screen color. Works for VLC, some games, etc.
 
 # use the LIFX LAN protocol via the excellent library by Meghan Clark
 # https://github.com/mclarkk/lifxlan
-from lifxlan import * # 
+from lifxlan import *
 
-from PIL import ImageGrab
+from mss import mss
 from PIL import Image
 import time, os, colorsys
 
@@ -17,16 +17,16 @@ def rgb2hsv(r, g, b):
     h = h * 0xffff
     s = s * 0xffff
     v = v * 0xffff
-    return h , s, v
+    return(h, s, v)
 
 def main():
     # start with the LIFX business...
-    lifx = LifxLAN(1)
-    print "Discovering lights..."
+    lifx = LifxLAN(None)
+    print("Discovering lights...")
     devices = lifx.get_lights()
     for d in devices:
-        print "{} ({}) HSBK: {}".format(d.get_label(), d.mac_addr, d.get_color())
-    print
+        print("{} ({}) HSBK: {}".format(d.get_label(), d.mac_addr, d.get_color()))
+    print()
 
     # the block of data to analyze.
     # PIL resizing to 1x1 seems to do strange things; a bigger box works better
@@ -37,14 +37,23 @@ def main():
 
     # screen scanning loop
     while True:
-        img = ImageGrab.grab()
-        t1 = time.clock()
+        with mss() as sct: image_file = sct.shot()
+        img_org = Image.open(image_file)
+        width_org, height_org = img_org.size
+        width = int(width_org * 0.75)
+        height = int(height_org * 0.75)
+        # best down-sizing filter
+        #img_resized = img_org.resize((width, height), Image.ANTIALIAS)
+        # quickest down-sizing filter
+        img_resized = img_org.resize((width, height), Image.NEAREST)
+        img = img_resized
+        t1 = time.process_time()
         # let PIL to shrink the image into a more manageable size
         # (just few ms in your average machine)
         img = img.resize((rx, ry))
         red = green = blue = 0
-        for y in xrange(0, img.size[1]):
-            for x in xrange(0, img.size[0]):
+        for y in range(0, img.size[1]):
+            for x in range(0, img.size[0]):
                 c = img.getpixel((x,y))
                 red = red + c[0]
                 green = green + c[1]
@@ -52,10 +61,10 @@ def main():
         red = red / totpixels
         green = green / totpixels
         blue = blue / totpixels
-        t2 = time.clock()
+        t2 = time.process_time()
 
-        print "\rRGB %3d %3d %3d" % (red, green, blue), 
-        print "- Time %2.4f" % (t2-t1), 
+        print("\rRGB {:.1f} {:.1f} {:.1f}".format(red, green, blue))
+        print("- Time {}".format(t2-t1))
 
         h, s, v = rgb2hsv(red, green, blue)
         color = (h, s, v, 0)