--- /dev/null
+#! /usr/bin/env python
+
+print "OpenCV Python version of contours"
+
+# import the necessary things for OpenCV
+from opencv import cv
+from opencv import highgui
+
+# some default constants
+_SIZE = 500
+_DEFAULT_LEVEL = 3
+
+# definition of some colors
+_red = cv.cvScalar (0, 0, 255, 0);
+_green = cv.cvScalar (0, 255, 0, 0);
+_white = cv.cvRealScalar (255)
+_black = cv.cvRealScalar (0)
+
+# the callback on the trackbar, to set the level of contours we want
+# to display
+def on_trackbar (position):
+
+ # create the image for putting in it the founded contours
+ contours_image = cv.cvCreateImage (cv.cvSize (_SIZE, _SIZE), 8, 3)
+
+ # compute the real level of display, given the current position
+ levels = position - 3
+
+ # initialisation
+ _contours = contours
+
+ if levels <= 0:
+ # zero or negative value
+ # => get to the nearest face to make it look more funny
+ _contours = contours.h_next.h_next.h_next
+
+ # first, clear the image where we will draw contours
+ cv.cvSetZero (contours_image)
+
+ # draw contours in red and green
+ cv.cvDrawContours (contours_image, _contours,
+ _red, _green,
+ levels, 3, cv.CV_AA,
+ cv.cvPoint (0, 0))
+
+ # finally, show the image
+ highgui.cvShowImage ("contours", contours_image)
+
+if __name__ == '__main__':
+
+ # create the image where we want to display results
+ image = cv.cvCreateImage (cv.cvSize (_SIZE, _SIZE), 8, 1)
+
+ # start with an empty image
+ cv.cvSetZero (image)
+
+ # draw the original picture
+ for i in range (6):
+ dx = (i % 2) * 250 - 30
+ dy = (i / 2) * 150
+
+ cv.cvEllipse (image,
+ cv.cvPoint (dx + 150, dy + 100),
+ cv.cvSize (100, 70),
+ 0, 0, 360, _white, -1, 8, 0)
+ cv.cvEllipse (image,
+ cv.cvPoint (dx + 115, dy + 70),
+ cv.cvSize (30, 20),
+ 0, 0, 360, _black, -1, 8, 0)
+ cv.cvEllipse (image,
+ cv.cvPoint (dx + 185, dy + 70),
+ cv.cvSize (30, 20),
+ 0, 0, 360, _black, -1, 8, 0)
+ cv.cvEllipse (image,
+ cv.cvPoint (dx + 115, dy + 70),
+ cv.cvSize (15, 15),
+ 0, 0, 360, _white, -1, 8, 0)
+ cv.cvEllipse (image,
+ cv.cvPoint (dx + 185, dy + 70),
+ cv.cvSize (15, 15),
+ 0, 0, 360, _white, -1, 8, 0)
+ cv.cvEllipse (image,
+ cv.cvPoint (dx + 115, dy + 70),
+ cv.cvSize (5, 5),
+ 0, 0, 360, _black, -1, 8, 0)
+ cv.cvEllipse (image,
+ cv.cvPoint (dx + 185, dy + 70),
+ cv.cvSize (5, 5),
+ 0, 0, 360, _black, -1, 8, 0)
+ cv.cvEllipse (image,
+ cv.cvPoint (dx + 150, dy + 100),
+ cv.cvSize (10, 5),
+ 0, 0, 360, _black, -1, 8, 0)
+ cv.cvEllipse (image,
+ cv.cvPoint (dx + 150, dy + 150),
+ cv.cvSize (40, 10),
+ 0, 0, 360, _black, -1, 8, 0)
+ cv.cvEllipse (image,
+ cv.cvPoint (dx + 27, dy + 100),
+ cv.cvSize (20, 35),
+ 0, 0, 360, _white, -1, 8, 0)
+ cv.cvEllipse (image,
+ cv.cvPoint (dx + 273, dy + 100),
+ cv.cvSize (20, 35),
+ 0, 0, 360, _white, -1, 8, 0)
+
+ # create window and display the original picture in it
+ highgui.cvNamedWindow ("image", 1)
+ highgui.cvShowImage ("image", image)
+
+ # create the storage area
+ storage = cv.cvCreateMemStorage (0)
+
+ # find the contours
+ nb_contours, contours = cv.cvFindContours (image,
+ storage,
+ cv.sizeof_CvContour,
+ cv.CV_RETR_TREE,
+ cv.CV_CHAIN_APPROX_SIMPLE,
+ cv.cvPoint (0,0))
+
+ # comment this out if you do not want approximation
+ contours = cv.cvApproxPoly (contours, cv.sizeof_CvContour,
+ storage,
+ cv.CV_POLY_APPROX_DP, 3, 1)
+
+ # create the window for the contours
+ highgui.cvNamedWindow ("contours", 1)
+
+ # create the trackbar, to enable the change of the displayed level
+ highgui.cvCreateTrackbar ("levels+3", "contours", 3, 7, on_trackbar)
+
+ # call one time the callback, so we will have the 1st display done
+ on_trackbar (_DEFAULT_LEVEL)
+
+ # wait a key pressed to end
+ highgui.cvWaitKey (0)
projects / opencv / blobdiff