"atomic bomb" commit. Reorganized OpenCV directory structure

samples/python/fback.py

@@ -0,0 +1,55 @@
+#!/usr/bin/env python
+
+from cv import *
+
+class FBackDemo:
+    def __init__(self):
+        self.capture = CaptureFromCAM(0)
+        self.mv_step = 16
+        self.mv_scale = 1.5
+        self.mv_color = (0, 255, 0)
+        self.cflow = None
+        self.flow = None
+        
+        NamedWindow( "Optical Flow", 1 )
+
+        print( "Press ESC - quit the program\n" )
+
+    def draw_flow(self, flow, prevgray):
+        """ Returns a nice representation of a hue histogram """
+
+        CvtColor(prevgray, self.cflow, CV_GRAY2BGR)
+        for y in range(0, flow.height, self.mv_step):
+            for x in range(0, flow.width, self.mv_step):
+                fx, fy = flow[y, x]
+                Line(self.cflow, (x,y), (x+fx,y+fy), self.mv_color)
+                Circle(self.cflow, (x,y), 2, self.mv_color, -1)
+        ShowImage("Optical Flow", self.cflow)
+
+    def run(self):
+        first_frame = True
+        
+        while True:
+            frame = QueryFrame( self.capture )
+
+            if first_frame:
+                gray = CreateImage(GetSize(frame), 8, 1)
+                prev_gray = CreateImage(GetSize(frame), 8, 1)
+                flow = CreateImage(GetSize(frame), 32, 2)
+                self.cflow = CreateImage(GetSize(frame), 8, 3)
+                
+            CvtColor(frame, gray, CV_BGR2GRAY)
+            if not first_frame:
+                CalcOpticalFlowFarneback(prev_gray, gray, flow,
+                    pyr_scale=0.5, levels=3, winsize=15,
+                    iterations=3, poly_n=5, poly_sigma=1.2, flags=0)
+                self.draw_flow(flow, prev_gray)
+                c = WaitKey(7)
+                if c in [27, ord('q'), ord('Q')]:
+                    break
+            prev_gray, gray = gray, prev_gray        
+            first_frame = False
+
+if __name__=="__main__":
+    demo = FBackDemo()
+    demo.run()