diff --git a/README.md b/README.md
index 428909d..6eec0fa 100644
--- a/README.md
+++ b/README.md
@@ -1,20 +1,22 @@
 # linedraw
 Convert images to vectorized line drawings for plotters.
-![Alt text](/screenshots/1.png?raw=true "")
+![Alt text](./screenshots/1.png?raw=true "")
 
 - Exports polyline-only svg file with optimized stroke order for plotters;
 - Sketchy style powered by Perlin noise;
 - Contour-only or hatch-only modes.
 
 ## Dependencies
-Python 2, PIL/Pillow, numpy, OpenCV (Optional for better performance)
+Python 2 or 3, PIL/Pillow, numpy, OpenCV (Optional for better performance)
 
 ## Usage
 Convert an image to line drawing and export .SVG format:
+
 ```shell
 $ python linedraw.py -i input.jpg -o output.svg
 ```
 Command specs:
+
 ```
 usage: linedraw.py [-h] [-i [INPUT_PATH]] [-o [OUTPUT_PATH]] [-b] [-nc] [-nh]
                    [--no_cv] [--hatch_size [HATCH_SIZE]]
@@ -38,6 +40,7 @@ optional arguments:
                         Level of contour simplification. eg. 1, 2, 3
 ```
 Python:
+
 ```python
 import linedraw
 lines = linedraw.sketch("path/to/img.jpg")  # return list of polylines, eg.
diff --git a/linedraw.py b/linedraw.py
index 26cd233..ac922de 100644
--- a/linedraw.py
+++ b/linedraw.py
@@ -22,11 +22,11 @@ try:
     import numpy as np
     import cv2
 except:
-    print "Cannot import numpy/openCV. Switching to NO_CV mode."
+    print("Cannot import numpy/openCV. Switching to NO_CV mode.")
     no_cv = True
 
 def find_edges(IM):
-    print "finding edges..."
+    print("finding edges...")
     if no_cv:
         #appmask(IM,[F_Blur])
         appmask(IM,[F_SobelX,F_SobelY])
@@ -39,7 +39,7 @@ def find_edges(IM):
 
 
 def getdots(IM):
-    print "getting contour points..."
+    print("getting contour points...")
     PX = IM.load()
     dots = []
     w,h = IM.size
@@ -58,7 +58,7 @@ def getdots(IM):
     return dots
     
 def connectdots(dots):
-    print "connecting contour points..."
+    print("connecting contour points...")
     contours = []
     for y in range(len(dots)):
         for x,v in dots[y]:
@@ -91,7 +91,7 @@ def connectdots(dots):
 
 
 def getcontours(IM,sc=2):
-    print "generating contours..."
+    print("generating contours...")
     IM = find_edges(IM)
     IM1 = IM.copy()
     IM2 = IM.rotate(-90,expand=True).transpose(Image.FLIP_LEFT_RIGHT)
@@ -128,7 +128,7 @@ def getcontours(IM,sc=2):
 
 
 def hatch(IM,sc=16):
-    print "hatching..."
+    print("hatching...")
     PX = IM.load()
     w,h = IM.size
     lg1 = []
@@ -184,13 +184,13 @@ def sketch(path):
 
     lines = []
     if draw_contours:
-        lines += getcontours(IM.resize((resolution/contour_simplify,resolution/contour_simplify*h/w)),contour_simplify)
+        lines += getcontours(IM.resize((resolution//contour_simplify,resolution//contour_simplify*h//w)),contour_simplify)
     if draw_hatch:
-        lines += hatch(IM.resize((resolution/hatch_size,resolution/hatch_size*h/w)),hatch_size)
+        lines += hatch(IM.resize((resolution//hatch_size,resolution//hatch_size*h//w)),hatch_size)
 
     lines = sortlines(lines)
     if show_bitmap:
-        disp = Image.new("RGB",(resolution,resolution*h/w),(255,255,255))
+        disp = Image.new("RGB",(resolution,resolution*h//w),(255,255,255))
         draw = ImageDraw.Draw(disp)
         for l in lines:
             draw.line(l,(0,0,0),5)
@@ -199,13 +199,13 @@ def sketch(path):
     f = open(export_path,'w')
     f.write(makesvg(lines))
     f.close()
-    print len(lines), "strokes."
-    print "done."
+    print("strokes.")
+    print("done.")
     return lines
 
 
 def makesvg(lines):
-    print "generating svg file..."
+    print("generating svg file...")
     out = '<svg xmlns="http://www.w3.org/2000/svg" version="1.1">'
     for l in lines:
         l = ",".join([str(p[0]*0.5)+","+str(p[1]*0.5) for p in l])
diff --git a/strokesort.py b/strokesort.py
index 7f1ac9a..748e6d5 100644
--- a/strokesort.py
+++ b/strokesort.py
@@ -4,7 +4,7 @@ from util import *
 
 
 def sortlines(lines):
-    print "optimizing stroke sequence..."
+    print("optimizing stroke sequence...")
     clines = lines[:]
     slines = [clines.pop(0)]
     while clines != []: