diff --git a/pixelflut.py b/pixelflut.py
index ba5359d..5fabc09 100755
--- a/pixelflut.py
+++ b/pixelflut.py
@@ -4,11 +4,11 @@ import PIL
 from PIL import Image, ImageColor
 import argparse
 import threading
+from sys import exit
 
 sizex = 800    
 sizey = 600
 
-
 XSPLIT = 5
 YSPLIT = 5
 
@@ -22,13 +22,19 @@ framebuffer = Image.new("RGBA", (sizex, sizey), (0,0,0,0))
 parser = argparse.ArgumentParser()
 mode = parser.add_mutually_exclusive_group(required=True)
 mode.add_argument("--color")
-mode.add_argument("--image")
+mode.add_argument("--image", metavar="FILENAME")
 parser.add_argument("--host", default="fsi-hase.fsmi.uni-karlsruhe.de")
 parser.add_argument("--port", "-p", type=int, default="3141")
-parser.add_argument("--dumb", action="store_true")
 parser.add_argument("--yoffset", default=19, type=int)
-parser.add_argument("--repeat", action="store_true")
-parser.add_argument("--animate", action="store_true")
+parser.add_argument("--xoffset", default=0, type=int)
+effect = parser.add_mutually_exclusive_group(required=False)
+effect.add_argument("--repeat", action="store_true")
+effect.add_argument("--animate", type=int, const=5, nargs='?', metavar="STEPSIZE")
+parser.add_argument("--bounce", action="store_true")
+
+if args.bounce and not args.animate:
+    print("--bounce requires --animate")
+    exit(1)
 
 args = parser.parse_args()
 
@@ -39,8 +45,6 @@ class DrawThread(threading.Thread):
         xto = self._kwargs["xto"]
         yto = self._kwargs["yto"]
 
-        #print(xfrom, xto, yfrom, yto)
-
         s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
         s.connect((args.host, args.port))
         buf = bytearray()
@@ -50,7 +54,7 @@ class DrawThread(threading.Thread):
             for y in range(yfrom,yto):
                 if framebuffer.getpixel((x,y))[3] != 0:
                     value = b"%02X%02X%02X%02X"%framebuffer.getpixel((x,y))
-                    buf += b"PX %d %d %b\n"%(x,y,value)
+                    buf += b"PX %d %d %b\n"%(x+args.xoffset,y+args.yoffset,value)
 
         s.send(buf)
         while args.repeat:
@@ -123,7 +127,7 @@ elif args.image:
         dirtybox = (0,0,min(image.size[0], sizex),min(image.size[1], sizey))
     draw()
     while args.animate:
-        coordinates = (coordinates[0] + 5, coordinates[1] + 5)
+        coordinates = (coordinates[0] + args.animate, coordinates[1] + args.animate)
         if coordinates[0] >= sizex or coordinates[1] >= sizey:
             break
         dirtybox = (*coordinates, min(image.size[0]+coordinates[0], sizex), min(image.size[1]+coordinates[1], sizey))