Add the first three worked examples.

firstprogram.py

@@ -0,0 +1,15 @@
+#!/usr/bin/python
+
+import sys
+from opencv import highgui
+
+def show(filename):
+  img =  highgui.cvLoadImage(filename)
+  highgui.cvNamedWindow("Example1", highgui.CV_WINDOW_AUTOSIZE)
+  highgui.cvShowImage("Example1", img)
+  highgui.cvWaitKey(0)
+  highgui.cvDestroyWindow("Example1")  
+
+if __name__ == "__main__":
+  show(sys.argv[1])
+  sys.exit(0)

secondprogram.py

@@ -0,0 +1,25 @@
+#!/usr/bin/python
+
+import sys
+from opencv import highgui
+
+def showavi(filename):
+  highgui.cvNamedWindow("Example2", highgui.CV_WINDOW_AUTOSIZE)
+  capture = highgui.cvCreateFileCapture(filename)
+
+  while True:
+    frame = highgui.cvQueryFrame(capture)
+    if not frame:
+      break
+    highgui.cvShowImage("Example2", frame)
+
+    c = highgui.cvWaitKey(100)
+    if c == '\x1b': # escape key
+      break
+
+  highgui.cvReleaseCapture(capture)
+  highgui.cvDestroyWindow("Example2")
+
+if __name__ == "__main__":
+  showavi(sys.argv[1])
+  sys.exit(0)

thirdprogram.py

@@ -0,0 +1,37 @@
+#!/usr/bin/python
+
+import sys
+from opencv import highgui
+
+capture = None
+slider_pos = 0
+
+def on_trackbar_slide(position):
+  highgui.cvSetCaptureProperty(capture, highgui.CV_CAP_PROP_POS_FRAMES, position)
+
+def showavi(filename):
+  highgui.cvNamedWindow("Example3", highgui.CV_WINDOW_AUTOSIZE)
+  global capture
+  capture = highgui.cvCreateFileCapture(filename)
+
+  frames = int(highgui.cvGetCaptureProperty(capture, highgui.CV_CAP_PROP_FRAME_COUNT))
+
+  if frames != 0:
+    highgui.cvCreateTrackbar("Position", "Example3", slider_pos, frames, on_trackbar_slide)
+
+  while True:
+    frame = highgui.cvQueryFrame(capture)
+    if not frame:
+      break
+    highgui.cvShowImage("Example3", frame)
+
+    c = highgui.cvWaitKey(100)
+    if c == '\x1b': # escape key
+      break
+
+  highgui.cvReleaseCapture(capture)
+  highgui.cvDestroyWindow("Example3")
+
+if __name__ == "__main__":
+  showavi(sys.argv[1])
+  sys.exit(0)