canny edge detection

Author: abidrahmank

example_2_6.py

@@ -0,0 +1,34 @@
+''' 
+Referred to example 2.6 in the book "Learning OpenCV: Computer Vision with the OpenCV Library"
+
+Example 2-6. The Canny edge detector writes its output to a single channel (grayscale) image
+
+Brought to you by Abid.K	--mail me at [email protected]
+'''
+########################################################################################
+import cv
+image=cv.LoadImage("test.jpg")
+cv.NamedWindow("input")
+cv.NamedWindow("output")
+
+def doCanny(image,lowThresh,highThresh,aperture):
+# 	i have changed code a little bit from text book. With example in text book, you have to load 		grayscale image. But now you can load any image, no matter if RGB or GRAYSCALE
+#	output image with single channel
+	out=cv.CreateImage(cv.GetSize(image),cv.IPL_DEPTH_8U,1)
+#	canny only handles grayscale images. So convert RGB to grayscale
+	if image.nChannels != 1:
+		cv.CvtColor(image,out,cv.CV_RGB2GRAY)
+		cv.Canny(out,out,lowThresh,highThresh,aperture)
+	else:
+		cv.Canny(image,out,lowThresh,highThresh,aperture)
+	return out
+
+image=cv.LoadImage("test.jpg")
+#	some arbitrary values are given as parameters
+out=doCanny(image,100,200,3)
+cv.ShowImage("input",image)
+cv.ShowImage("output",out)
+cv.WaitKey(0)
+cv.DestroyWindow("input")
+cv.DestroyWindow("output")
+########################################################################################