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136 lines
4.2 KiB
Python
Executable File
136 lines
4.2 KiB
Python
Executable File
#! /usr/bin/env python
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print "OpenCV Python version of contours"
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# import the necessary things for OpenCV
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import cv
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# some default constants
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_SIZE = 500
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_DEFAULT_LEVEL = 3
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# definition of some colors
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_red = (0, 0, 255, 0);
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_green = (0, 255, 0, 0);
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_white = cv.RealScalar (255)
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_black = cv.RealScalar (0)
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# the callback on the trackbar, to set the level of contours we want
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# to display
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def on_trackbar (position):
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# create the image for putting in it the founded contours
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contours_image = cv.CreateImage ( (_SIZE, _SIZE), 8, 3)
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# compute the real level of display, given the current position
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levels = position - 3
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# initialisation
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_contours = contours
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if levels <= 0:
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# zero or negative value
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# => get to the nearest face to make it look more funny
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_contours = contours.h_next().h_next().h_next()
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# first, clear the image where we will draw contours
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cv.SetZero (contours_image)
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# draw contours in red and green
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cv.DrawContours (contours_image, _contours,
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_red, _green,
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levels, 3, cv.CV_AA,
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(0, 0))
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# finally, show the image
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cv.ShowImage ("contours", contours_image)
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if __name__ == '__main__':
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# create the image where we want to display results
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image = cv.CreateImage ( (_SIZE, _SIZE), 8, 1)
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# start with an empty image
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cv.SetZero (image)
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# draw the original picture
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for i in range (6):
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dx = (i % 2) * 250 - 30
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dy = (i / 2) * 150
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cv.Ellipse (image,
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(dx + 150, dy + 100),
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(100, 70),
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0, 0, 360, _white, -1, 8, 0)
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cv.Ellipse (image,
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(dx + 115, dy + 70),
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(30, 20),
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0, 0, 360, _black, -1, 8, 0)
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cv.Ellipse (image,
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(dx + 185, dy + 70),
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(30, 20),
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0, 0, 360, _black, -1, 8, 0)
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cv.Ellipse (image,
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(dx + 115, dy + 70),
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(15, 15),
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0, 0, 360, _white, -1, 8, 0)
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cv.Ellipse (image,
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(dx + 185, dy + 70),
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(15, 15),
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0, 0, 360, _white, -1, 8, 0)
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cv.Ellipse (image,
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(dx + 115, dy + 70),
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(5, 5),
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0, 0, 360, _black, -1, 8, 0)
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cv.Ellipse (image,
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(dx + 185, dy + 70),
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(5, 5),
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0, 0, 360, _black, -1, 8, 0)
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cv.Ellipse (image,
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(dx + 150, dy + 100),
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(10, 5),
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0, 0, 360, _black, -1, 8, 0)
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cv.Ellipse (image,
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(dx + 150, dy + 150),
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(40, 10),
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0, 0, 360, _black, -1, 8, 0)
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cv.Ellipse (image,
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(dx + 27, dy + 100),
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(20, 35),
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0, 0, 360, _white, -1, 8, 0)
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cv.Ellipse (image,
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(dx + 273, dy + 100),
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(20, 35),
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0, 0, 360, _white, -1, 8, 0)
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# create window and display the original picture in it
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cv.NamedWindow ("image", 1)
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cv.ShowImage ("image", image)
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# create the storage area
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storage = cv.CreateMemStorage (0)
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# find the contours
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contours = cv.FindContours(image,
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storage,
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cv.CV_RETR_TREE,
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cv.CV_CHAIN_APPROX_SIMPLE,
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(0,0))
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# comment this out if you do not want approximation
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contours = cv.ApproxPoly (contours,
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storage,
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cv.CV_POLY_APPROX_DP, 3, 1)
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# create the window for the contours
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cv.NamedWindow ("contours", 1)
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# create the trackbar, to enable the change of the displayed level
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cv.CreateTrackbar ("levels+3", "contours", 3, 7, on_trackbar)
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# call one time the callback, so we will have the 1st display done
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on_trackbar (_DEFAULT_LEVEL)
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# wait a key pressed to end
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cv.WaitKey (0)
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