diff --git a/tests/data/images/12_654_1580.png b/tests/data/images/12_654_1580.png
new file mode 100644
index 000000000..0f15a353c
Binary files /dev/null and b/tests/data/images/12_654_1580.png differ
diff --git a/tests/python_tests/image_encoding_speed_test.py b/tests/python_tests/image_encoding_speed_test.py
index 8050f3497..14a41bbe5 100644
--- a/tests/python_tests/image_encoding_speed_test.py
+++ b/tests/python_tests/image_encoding_speed_test.py
@@ -18,14 +18,23 @@ combinations = ['png',
                 'png8:m=h',
                 'png8:m=o:t=0',
                 'png8:m=o:t=1',
+                'png8:m=o:t=2',
                 'png8:m=h:t=0',
                 'png8:m=h:t=1',
+                'png8:m=h:t=2',
                 'png:z=1',
                 'png8:z=1',
                 'png8:z=1:m=o',
                 'png8:z=1:m=h',
-                'png8:z=1:c=50',
                 'png8:z=1:c=1',
+                'png8:z=1:c=24',
+                'png8:z=1:c=64',
+                'png8:z=1:c=128',
+                'png8:z=1:c=200',
+                'png8:z=1:c=255',
+                'png8:z=9:c=64',
+                'png8:z=9:c=128',
+                'png8:z=9:c=200',
                 'png8:z=1:c=50:m=h',
                 'png8:z=1:c=1:m=o',
                 'png8:z=1:c=1:m=o:s=filtered',
@@ -53,11 +62,11 @@ def do_encoding():
         min_ = min(set)*1000
         avg = (sum(set)/len(set))*1000
         name = func.__name__ + ' ' + format
-        results[name] = [avg,min_,elapsed*1000,name]
-        sortable[name] = [avg]
+        results[name] = [avg,min_,elapsed*1000,name,len(func())]
+        sortable[name] = [min_]
 
     def blank():
-        eval('image.tostring("%s")' % c)
+        return eval('image.tostring("%s")' % c)
     blank_im = mapnik.Image(512,512)
 
     for c in combinations:
@@ -65,7 +74,7 @@ def do_encoding():
         run(blank,blank_im,c,t)
 
     def solid():
-        eval('image.tostring("%s")' % c)
+        return eval('image.tostring("%s")' % c)
     solid_im = mapnik.Image(512,512)
     solid_im.background = mapnik.Color("#f2efe9")
 
@@ -74,7 +83,7 @@ def do_encoding():
         run(solid,solid_im,c,t)
 
     def many_colors():
-        eval('image.tostring("%s")' % c)
+        return eval('image.tostring("%s")' % c)
     # lots of colors: http://tile.osm.org/13/4194/2747.png
     many_colors_im = mapnik.Image.open('../data/images/13_4194_2747.png')
 
@@ -82,13 +91,23 @@ def do_encoding():
         t = Timer(many_colors)
         run(many_colors,many_colors_im,c,t)
 
+    def aerial_24():
+        return eval('image.tostring("%s")' % c)
+    aerial_24_im = mapnik.Image.open('../data/images/12_654_1580.png')
+
+    for c in combinations:
+        t = Timer(aerial_24)
+        run(aerial_24,aerial_24_im,c,t)
+
     for key, value in sorted(sortable.iteritems(), key=lambda (k,v): (v,k)):
         s = results[key]
         avg = str(s[0])[:6]
         min_ = str(s[1])[:6]
         elapsed = str(s[2])[:6]
+        percent_reduction = s[4]
         name = s[3]
-        print 'avg: %sms | min: %sms | total: %sms <-- %s' % (min_,avg,elapsed,name)
+        size = s[4]
+        print 'avg: %sms | min: %sms | total: %sms | len: %s <-- %s' % (min_,avg,elapsed,size,name)
 
 
 if __name__ == "__main__":